Use previous version of some gems

Gemfile.lock

@@ -133,7 +133,6 @@ GEM
       descendants_tracker (~> 0.0.4)
       ice_nine (~> 0.11.0)
       thread_safe (~> 0.3, >= 0.3.1)
-    base64 (0.2.0)
     batch-loader (1.5.0)
     bcrypt (3.1.19)
     better_html (1.0.16)
@@ -600,7 +599,7 @@ GEM
       rack (>= 1.2, < 4)
       snaky_hash (~> 2.0)
       version_gem (~> 1.1)
-    omniauth (2.1.2)
+    omniauth (2.1.1)
       hashie (>= 3.4.6)
       rack (>= 2.2.3)
       rack-protection
@@ -657,9 +656,8 @@ GEM
       rack (>= 1.0, < 4)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
-    rack-protection (3.2.0)
-      base64 (>= 0.1.0)
-      rack (~> 2.2, >= 2.2.4)
+    rack-protection (3.0.6)
+      rack
     rack-proxy (0.7.6)
       rack
     rack-test (2.1.0)
@@ -913,8 +911,10 @@ DEPENDENCIES
   image_processing (>= 1.2)
   letter_opener_web (~> 1.3)
   listen (~> 3.1)
+  omniauth (= 2.1.1)
   omniauth-decidim
   puma (>= 5.0.0)
+  rack-protection (= 3.0.6)
   rspec
   rubocop-faker
   sentry-rails