Update mail_room

Gemfile

@@ -286,7 +286,7 @@ gem "newrelic_rpm", '~> 3.9.4.245'
 gem 'octokit', '~> 3.7.0'
-gem "mail_room", "~> 0.5.1"
+gem "mail_room", "~> 0.5.2"
 gem 'email_reply_parser', '~> 0.5.8'

Gemfile.lock

@@ -384,7 +384,7 @@ GEM
       systemu (~> 2.6.2)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
-    mail_room (0.5.1)
+    mail_room (0.5.2)
     method_source (0.8.2)
     mime-types (1.25.1)
     mimemagic (0.3.0)
@@ -848,7 +848,7 @@ DEPENDENCIES
   jquery-ui-rails (~> 4.2.1)
   kaminari (~> 0.16.3)
   letter_opener (~> 1.1.2)
-  mail_room (~> 0.5.1)
+  mail_room (~> 0.5.2)
   minitest (~> 5.7.0)
   mousetrap-rails (~> 1.4.6)
   mysql2 (~> 0.3.16)