Bump perfect-scrollbar

Gemfile

@@ -112,7 +112,7 @@ source "https://rails-assets.org" do
 
   gem "rails-assets-jquery-placeholder",            "2.3.1"
   gem "rails-assets-jquery-textchange",             "0.2.3"
-  gem "rails-assets-perfect-scrollbar",             "0.6.11"
+  gem "rails-assets-perfect-scrollbar",             "0.6.12"
   gem "rails-assets-autosize",                      "3.0.17"
   gem "rails-assets-blueimp-gallery",               "2.21.3"
 end

Gemfile.lock

@@ -680,7 +680,7 @@ GEM
     rails-assets-markdown-it-sanitizer (0.4.2)
     rails-assets-markdown-it-sub (1.0.0)
     rails-assets-markdown-it-sup (1.0.0)
-    rails-assets-perfect-scrollbar (0.6.11)
+    rails-assets-perfect-scrollbar (0.6.12)
     rails-deprecated_sanitizer (1.0.3)
       activesupport (>= 4.2.0.alpha)
     rails-dom-testing (1.0.7)
@@ -1012,7 +1012,7 @@ DEPENDENCIES
   rails-assets-markdown-it-sanitizer (= 0.4.2)!
   rails-assets-markdown-it-sub (= 1.0.0)!
   rails-assets-markdown-it-sup (= 1.0.0)!
-  rails-assets-perfect-scrollbar (= 0.6.11)!
+  rails-assets-perfect-scrollbar (= 0.6.12)!
   rails-i18n (= 4.0.8)
   rails-timeago (= 2.11.0)
   rails_admin (= 0.8.1)