replace django-babel temporary fork with maintained fork, enmerkar (#16840)

requirements/prod.txt

@@ -253,6 +253,9 @@ email-reply-parser==0.5.12 \
     --hash=sha256:d051cfa8f54046f7399553aae57f17f62bf1652f83e3e9970fd109c0f24a880c \
     --hash=sha256:3499c02284679e020acf8aa30ef9e43c62f9ab5ccee0a35bfac85a0c1fa685fd \
     --hash=sha256:9dbf3eca69990932234f09e7f50aa73756574fc1f88e88c324fec1a741ee6a74
+enmerkar==0.7.1 \
+    --hash=sha256:ba5a79e022963580c994ce8f4fe8477d574159adbe86e5271b1a3d4127b8794d \
+    --hash=sha256:a4a6c859b4ed293deee40ff61d6695b3ff7bc153770a1799f2be872181282e00
 feedparser==6.0.2 \
     --hash=sha256:f596c4b34fb3e2dc7e6ac3a8191603841e8d5d267210064e94d4238737452ddd \
     --hash=sha256:1b00a105425f492f3954fd346e5b524ca9cef3a4bbf95b8809470e9857aa1074

requirements/prod_without_hash.txt

@@ -1,2 +0,0 @@
-## django 2 compatible version isn't released yet. Matches the django-compat branch
--e git+https://github.com/EnTeQuAk/django-babel@dbc113798aa4beabdfa2d00e6fef48248eb0f185#egg=django-babel