Check for presence of installer

src/freedombone

@@ -8802,6 +8802,10 @@ function install_gnu_social {
 
     # Create the configuration
     gnu_social_installer=/var/www/${MICROBLOG_DOMAIN_NAME}/htdocs/scripts/install_cli.php
+    if [ ! -f $gnu_social_installer ]; then
+        echo $'No GNU Social commandline installer found'
+        exit 53026
+    fi
     ${gnu_social_installer} --server "${MICROBLOG_DOMAIN_NAME}" \
                             --host="localhost" --database="gnusocial" \
                             --dbtype=mysql --username="root" -v \