Core/Opcodes: Fix compiler error in GCC

Thanks Nevan

Closes #7404

src/server/game/Server/Protocol/Opcodes.cpp

@@ -37,7 +37,7 @@ void InitOpcodes()
             sLog->outError(LOG_FILTER_NETWORKIO, "Tried to override handler of %s with %s (opcode %u)",             \
                 opcodeTable[opcode]->name, #opcode, opcode);                                                        \
         }                                                                                                           \
-        else opcodeTable[opcode] = new OpcodeHandler(#opcode, #opcode##"_COMPRESSED", status, processing, handler); \
+        else opcodeTable[opcode] = new OpcodeHandler(#opcode, #opcode "_COMPRESSED", status, processing, handler); \
     }
 
     memset(opcodeTable, 0, sizeof(opcodeTable));