Work around parens in the url regex

bookwyrm/outgoing.py

@@ -296,7 +296,7 @@ def find_mentions(content):
 def format_links(content):
     ''' detect and format links '''
     return re.sub(
-        r'([^(href=")]|^)(https?:\/\/(%s([\w\.\-_\/+&\?=:;,])*))' % \
+        r'([^(href=")]|^|\()(https?:\/\/(%s([\w\.\-_\/+&\?=:;,])*))' % \
                 regex.domain,
         r'\g<1><a href="\g<2>">\g<3></a>',
         content)