Fix MyMemory response handling

The problem is that we try to escape \r inside of the strings and that
fails if it's outside of the string.

Fixes #941
Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/machine/base.py

@@ -104,7 +104,7 @@ class MachineTranslation(object):
         if text.startswith('\xef\xbb\xbf'):
             text = text.decode('UTF-8-sig')
         # Replace literal \t
-        text = text.replace(
+        text = text.strip().replace(
             '\t', '\\t'
         ).replace(
             '\r', '\\r'

weblate/trans/tests/test_machine.py

@@ -59,6 +59,7 @@ GLOSBE_JSON = u'''
 }
 '''.encode('utf-8')
 MYMEMORY_JSON = u'''
+\r\n
 {"responseData":{"translatedText":"svět"},"responseDetails":"",
 "responseStatus":200,
 "matches":[