App/Toponaming: Fix Python 3.11 compile issue

Need to ensure the Qt 'slots' macro is undefined by including FCConfig.h.

src/App/StringHasher.h

@@ -23,6 +23,8 @@
 #ifndef APP_STRING_ID_H
 #define APP_STRING_ID_H
 
+#include <FCConfig.h>
+
 #include <bitset>
 #include <memory>