Remove more redundant virtual specifiers

`grep -nr "virtual " | grep -v googletest | grep " override" | grep -v overriden > ../redundant_virtual.txt`

```python
import os

with open("../redundant_virtual.txt") as f:
    for line in f:
        print()
        line: str = line.strip()
        print(line)
        tmp = line.split(":",2)
        file = tmp[0].strip()
        code = tmp[-1].strip()
        print(file)
        print(code)
        new_code = code.replace("virtual ", "", 1)
        # https://superuser.com/a/802490/578501
        command = f"export FIND='{code}' && export REPLACE='{new_code}' && ruby -p -i -e \"gsub(ENV['FIND'], ENV['REPLACE'])\" {file}"
        os.system(command)
```

AI/Nullkiller/Goals/BuildThis.h

@@ -40,7 +40,7 @@ namespace Goals
 		BuildThis(BuildingID Bid, const CGTownInstance * tid);
 
 		bool operator==(const BuildThis & other) const override;
-		virtual std::string toString() const override;
+		std::string toString() const override;
 		void accept(AIGateway * ai) override;
 	};
 }

AI/Nullkiller/Goals/BuyArmy.h

@@ -38,7 +38,7 @@ namespace Goals
 
 		bool operator==(const BuyArmy & other) const override;
 
-		virtual std::string toString() const override;
+		std::string toString() const override;
 
 		void accept(AIGateway * ai) override;
 	};

AI/Nullkiller/Goals/CGoal.h

@@ -92,7 +92,7 @@ namespace Goals
 
 		bool isElementar() const override { return true; }
 
-		virtual HeroPtr getHero() const override { return AbstractGoal::hero; }
+		HeroPtr getHero() const override { return AbstractGoal::hero; }
 
 		int getHeroExchangeCount() const override { return 0; }
 	};

AI/Nullkiller/Goals/CaptureObject.h

@@ -35,8 +35,8 @@ namespace Goals
 		}
 
 		bool operator==(const CaptureObject & other) const override;
-		virtual Goals::TGoalVec decompose() const override;
-		virtual std::string toString() const override;
+		Goals::TGoalVec decompose() const override;
+		std::string toString() const override;
 		bool hasHash() const override { return true; }
 		uint64_t getHash() const override;
 	};

AI/Nullkiller/Goals/CompleteQuest.h

@@ -29,8 +29,8 @@ namespace Goals
 		{
 		}
 
-		virtual Goals::TGoalVec decompose() const override;
-		virtual std::string toString() const override;
+		Goals::TGoalVec decompose() const override;
+		std::string toString() const override;
 		bool hasHash() const override { return true; }
 		uint64_t getHash() const override;
 

AI/Nullkiller/Goals/Composition.h

@@ -27,7 +27,7 @@ namespace Goals
 		}
 
 		bool operator==(const Composition & other) const override;
-		virtual std::string toString() const override;
+		std::string toString() const override;
 		void accept(AIGateway * ai) override;
 		Composition & addNext(const AbstractGoal & goal);
 		Composition & addNext(TSubgoal goal);

AI/Nullkiller/Goals/Invalid.h

@@ -37,7 +37,7 @@ namespace Goals
 			return true;
 		}
 
-		virtual std::string toString() const override
+		std::string toString() const override
 		{
 			return "Invalid";
 		}

AI/Nullkiller/Goals/RecruitHero.h

@@ -43,7 +43,7 @@ namespace Goals
 			return true;
 		}
 
-		virtual std::string toString() const override;
+		std::string toString() const override;
 		void accept(AIGateway * ai) override;
 	};
 }

AI/Nullkiller/Goals/StayAtTown.h

@@ -27,7 +27,7 @@ namespace Goals
 		StayAtTown(const CGTownInstance * town, AIPath & path);
 
 		bool operator==(const StayAtTown & other) const override;
-		virtual std::string toString() const override;
+		std::string toString() const override;
 		void accept(AIGateway * ai) override;
 		float getMovementWasted() const { return movementWasted; }
 	};