Bump ruby prof to 0.16

This solve issues with ruby builds with rubygems preload
see https://github.com/ruby-prof/ruby-prof/pull/191Signed-off-by: Rémy Coutable <remy@rymai.me>

CHANGELOG

@@ -7,6 +7,7 @@ v 8.13.0 (unreleased)
   - Fix robots.txt disallowing access to groups starting with "s" (Matt Harrison)
   - Only update issuable labels if they have been changed
   - Revoke button in Applications Settings underlines on hover.
+  - Update ruby-prof to 0.16.2. !6026 (Elan Ruusamäe)
   - Add organization field to user profile
   - Optimize GitHub importing for speed and memory
 

Gemfile

@@ -328,7 +328,7 @@ gem 'mail_room', '~> 0.8'
 
 gem 'email_reply_parser', '~> 0.5.8'
 
-gem 'ruby-prof', '~> 0.15.9'
+gem 'ruby-prof', '~> 0.16.2'
 
 ## CI
 gem 'activerecord-session_store', '~> 1.0.0'

Gemfile.lock

@@ -629,7 +629,7 @@ GEM
       rubocop (>= 0.40.0)
     ruby-fogbugz (0.2.1)
       crack (~> 0.4)
-    ruby-prof (0.15.9)
+    ruby-prof (0.16.2)
     ruby-progressbar (1.8.1)
     ruby-saml (1.3.0)
       nokogiri (>= 1.5.10)
@@ -942,7 +942,7 @@ DEPENDENCIES
   rubocop (~> 0.42.0)
   rubocop-rspec (~> 1.5.0)
   ruby-fogbugz (~> 0.2.1)
-  ruby-prof (~> 0.15.9)
+  ruby-prof (~> 0.16.2)
   sanitize (~> 2.0)
   sass-rails (~> 5.0.6)
   scss_lint (~> 0.47.0)