Core: Append single character to stream as character, not as a string

src/server/authserver/Realms/RealmList.cpp

@@ -46,7 +46,7 @@ void RealmList::UpdateRealm(uint32 ID, const std::string& name, const std::strin
 
     // Append port to IP address.
     std::ostringstream ss;
-    ss << address << ":" << port;
+    ss << address << ':' << port;
     realm.address = ss.str();
     realm.gamebuild = build;
 }