Handle with invalid manifests better

In other words, don't blow up and kill a whole checkupdates run just
because one version of one package has some invalid xml.

fdroidserver/common.py

@@ -1072,6 +1072,7 @@ def parse_androidmanifests(paths, app):
                     if matches:
                         vercode = matches.group(1)
         else:
+            try:
                 xml = parse_xml(path)
                 if "package" in xml.attrib:
                     s = xml.attrib["package"].encode('utf-8')
@@ -1085,6 +1086,8 @@ def parse_androidmanifests(paths, app):
                     a = xml.attrib["{http://schemas.android.com/apk/res/android}versionCode"].encode('utf-8')
                     if string_is_integer(a):
                         vercode = a
+            except Exception:
+                logging.warning("Problem with xml at {0}".format(path))
 
         # Remember package name, may be defined separately from version+vercode
         if package is None: