Upgrade Gitaly Gem to 14.0.0.pre.rc2

With release 14.0, Gitaly has introduced the ability to specify
in-memory remotes for the `UpdateRemoteMirror` RPC. We're about to start
using this new feature and thus need the new protobuf definitions which
include the new remote parameter.

Update the Gitaly Gem to 14.0.0.pre.rc2 to get the new definitions.

Gemfile

@@ -480,7 +480,7 @@ end
 gem 'spamcheck', '~> 0.1.0'
 
 # Gitaly GRPC protocol definitions
-gem 'gitaly', '~> 13.12.0.pre.rc1'
+gem 'gitaly', '~> 14.0.0.pre.rc2'
 
 # KAS GRPC protocol definitions
 gem 'kas-grpc', '~> 0.0.2'

Gemfile.lock

@@ -454,7 +454,7 @@ GEM
       rails (>= 3.2.0)
     git (1.7.0)
       rchardet (~> 1.8)
-    gitaly (13.12.0.pre.rc1)
+    gitaly (14.0.0.pre.rc2)
       grpc (~> 1.0)
     github-markup (1.7.0)
     gitlab (4.16.1)
@@ -1483,7 +1483,7 @@ DEPENDENCIES
   gettext (~> 3.3)
   gettext_i18n_rails (~> 1.8.0)
   gettext_i18n_rails_js (~> 1.3)
-  gitaly (~> 13.12.0.pre.rc1)
+  gitaly (~> 14.0.0.pre.rc2)
   github-markup (~> 1.7.0)
   gitlab-chronic (~> 0.10.5)
   gitlab-dangerfiles (~> 2.1.2)