folks: Update folks.git to 0.15.12 (#42)

Author: elementaryBot

io.elementary.contacts.json

@@ -121,8 +121,8 @@
                 {
                     "type": "git",
                     "url": "https://gitlab.gnome.org/GNOME/folks.git",
-                    "tag": "0.15.9",
-                    "commit": "f57424e8411bb0b005483593ed11025a838ab19f",
+                    "tag": "0.15.12",
+                    "commit": "b13bf053157213749b8ff6444255a7a71cb5ade4",
                     "x-checker-data": {
                         "type": "git",
                         "tag-pattern": "^([\\d.]+)$"