save hash and mime_type of avatar when receiving vCard from server

in case the avatar is not changed by the user we must resend the still valid hash.
if we do not save the hash here, gajim advertises an empty photo element after publishing the vCard,
which removes the avatar for all receiving clients of the photo element update

gajim/profile_window.py

@@ -29,6 +29,7 @@ from gi.repository import GdkPixbuf
 import base64
 import time
 import logging
+import hashlib
 
 from gajim import gtkgui_helpers
 from gajim import dialogs
@@ -229,6 +230,9 @@ class ProfileWindow:
                     continue
                 self.avatar_encoded = photo_encoded
                 photo_decoded = base64.b64decode(photo_encoded.encode('utf-8'))
+                self.avatar_sha = hashlib.sha1(photo_decoded).hexdigest()
+                if 'TYPE' in vcard_[i]:
+                    self.avatar_mime_type = vcard_[i]['TYPE']
                 pixbuf = gtkgui_helpers.get_pixbuf_from_data(photo_decoded)
                 if pixbuf is None:
                     continue