Fix: memory leak due to assigning result of strdup to a std::string

(cherry picked from commit 296194ad36)

src/newgrf.cpp

@@ -7563,7 +7563,7 @@ static void GRFInhibit(ByteReader *buf)
 		if (file != nullptr && file != _cur.grfconfig) {
 			grfmsg(2, "GRFInhibit: Deactivating file '%s'", file->GetDisplayPath());
 			GRFError *error = DisableGrf(STR_NEWGRF_ERROR_FORCEFULLY_DISABLED, file);
-			error->data = stredup(_cur.grfconfig->GetName());
+			error->data = _cur.grfconfig->GetName();
 		}
 	}
 }