Update to support when domain not provided will use relative path

Author: jackycute

lib/config.js

@@ -63,10 +63,13 @@ var dropbox = config.dropbox || false;
 var imgur = config.imgur || false;
 
 function getserverurl() {
-    var protocol = protocolusessl ? 'https://' : 'http://';
-    var url = protocol + domain;
-    if (urladdport && ((usessl && port != 443) || (!usessl && port != 80)))
-        url += ':' + port;
+    var url = '';
+    if (domain) {
+        var protocol = protocolusessl ? 'https://' : 'http://';
+        url = protocol + domain;
+        if (urladdport && ((usessl && port != 443) || (!usessl && port != 80)))
+            url += ':' + port;
+    }
     if (urlpath)
         url += '/' + urlpath;
     return url;