Fixes get_locale_prefixes() wrong paths (#874)

If default_locale was set, and a web page was visited that doesn't have a langauge code in the path in the URL, the URL path parts returned by get_locale_prefixes() was wrong (e.g. /hrst/ instead of /hr/test/).

pywb/rewrite/templateview.py

@@ -196,11 +196,11 @@ def get_locale_prefixes(context):
             orig_prefix = environ.get('pywb.app_prefix', '')
             coll = environ.get('SCRIPT_NAME', '')
 
-            if orig_prefix:
+            if orig_prefix and coll.startswith(orig_prefix):
                 coll = coll[len(orig_prefix):]
 
             curr_loc = environ.get('pywb_lang', '')
-            if curr_loc:
+            if curr_loc and coll.startswith('/' + curr_loc):
                 coll = coll[len(curr_loc) + 1:]
 
             for locale in loc_map.keys():