Remove unused variable

cockatrice/src/main.cpp

@@ -136,7 +136,6 @@ int main(int argc, char *argv[])
 
     qsrand(QDateTime::currentDateTime().toTime_t());
     
-    bool startMainProgram = true;
 #if QT_VERSION < 0x050000
     const QString dataDir = QDesktopServices::storageLocation(QDesktopServices::DataLocation);
 #else