Check that qvitter repo was installed

src/freedombone-utils-gnusocialtools

         git_clone $QVITTER_THEME_REPO Qvitter
     fi
 
+    if [ ! -d /var/www/${domain_name}/htdocs/local/plugins/Qvitter ]; then
+        echo $'Qvitter repo was not installed'
+        exit 835638
+    fi
+
     cd /var/www/${domain_name}/htdocs/local/plugins/Qvitter
     git checkout $QVITTER_THEME_COMMIT -b $QVITTER_THEME_COMMIT