Improve error when hostname cannot be found in a certificate.

Update error message with the hostname and more detail about what went wrong.  Hopefully this will help in diagnosing certificate/hostname issues.

Suggested by James Badger.

doc/xml/release.xml

@@ -40,6 +40,16 @@
                     </release-item>
                 </release-bug-list>
 
+                <release-improvement-list>
+                    <release-item>
+                        <release-item-contributor-list>
+                            <release-item-ideator id="james.badger"/>
+                        </release-item-contributor-list>
+
+                        <p>Improve error when hostname cannot be found in a certificate.</p>
+                    </release-item>
+                </release-improvement-list>
+
                 <release-development-list>
                     <release-item>
                         <p>Migrate <cmd>remote</cmd> command to C.</p>
@@ -6419,6 +6429,11 @@
             <contributor-id type="github">Edib</contributor-id>
         </contributor>
 
+        <contributor id="james.badger">
+            <contributor-name-display>James Badger</contributor-name-display>
+            <contributor-id type="github">openfirmware</contributor-id>
+        </contributor>
+
         <contributor id="james.chanco.jr">
             <contributor-name-display>James Chanco Jr</contributor-name-display>
             <contributor-id type="github">jameschancojr</contributor-id>

src/common/io/tls/client.c

@@ -402,7 +402,11 @@ tlsClientOpen(TlsClient *this)
             X509_free(certificate);
 
             if (!nameResult)
-                THROW(CryptoError, "unable to find matching hostname in certificate");
+            {
+                THROW_FMT(
+                    CryptoError,
+                    "unable to find hostname '%s' in certificate common name or subject alternative names", strPtr(this->host));
+            }
         }
 
         MEM_CONTEXT_BEGIN(this->memContext)

test/src/module/common/ioTlsTest.c

@@ -161,7 +161,7 @@ testRun(void)
             tlsClientOpen(
                 tlsClientNew(strNew("test3.pgbackrest.org"), 9443, 500, true,
                 strNewFmt("%s/" TEST_CERTIFICATE_PREFIX "-ca.crt", testRepoPath()), NULL)),
-            CryptoError, "unable to find matching hostname in certificate");
+            CryptoError, "unable to find hostname 'test3.pgbackrest.org' in certificate common name or subject alternative names");
 
         TEST_ERROR(
             tlsClientOpen(