Show text from clipboard in Add URL dialog only if it looks like an URL.

src/interface.py

@@ -32,6 +32,7 @@
 
 import os.path
 from itertools import izip
+import re
 import urllib
 
 import gettext
@@ -1177,8 +1178,9 @@ class DelugeGTK:
         dlg.vbox.pack_start(entry)
         clip = gtk.clipboard_get(selection='PRIMARY')
         text = clip.wait_for_text()
-        #watch out for an empty clipboard, TODO check for non url garbage 
         if text:
+            text = text.strip()
+            if re.search('^(https?|ftp)://', text):
                 entry.set_text(text)
         dlg.show_all()
         result = dlg.run()