wiki directory creation

src/freedombone-app-wiki

 
     ln -s /usr/share/dokuwiki /var/www/$WIKI_DOMAIN_NAME/htdocs
 
-    mkdir /var/lib/dokuwiki/custom
+    if [ ! -d /var/lib/dokuwiki/custom ]; then
+        mkdir /var/lib/dokuwiki/custom
+    fi
     cp /etc/dokuwiki/local.php.dist /var/lib/dokuwiki/custom/local.php
-    ln -s /var/lib/dokuwiki/custom/local.php /etc/dokuwiki/local.php
+    if [ ! -f /etc/dokuwiki/local.php ]; then
+        ln -s /var/lib/dokuwiki/custom/local.php /etc/dokuwiki/local.php
+    fi
 
     chown www-data /var/lib/dokuwiki/custom
     chown www-data /var/lib/dokuwiki/custom/local.php