Merge pull request #117 from pointhi/https_fix

print error if https rewrite directory is not found, #116

searx/https_rewrite.py

 import re
 from lxml import etree
 from os import listdir
-from os.path import isfile, join
+from os.path import isfile, isdir, join
 
 
 # https://gitweb.torproject.org/\
 
 # load all https rewrite rules
 def load_https_rules(rules_path):
-    # add / to path if not set yet
-    if rules_path[-1:] != '/':
-        rules_path += '/'
+    # check if directory exists
+    if not isdir(rules_path):
+        print("[E] directory not found: '" + rules_path + "'")
+        return
 
     # search all xml files which are stored in the https rule directory
     xml_files = [join(rules_path, f)