Apply suggestions from code review

Co-Authored-By: BevapDin <[email protected]>

src/field_type.cpp

@@ -29,7 +29,7 @@ std::string enum_to_string<game_message_type>( game_message_type data )
         case game_message_type::num_game_message_type:
             break;
     }
-    debugmsg( "Invalid side" );
+    debugmsg( "Invalid game_message_type" );
     abort();
 }