Bump google-protobuf to 3.6.1

It looks like gRPC may have worked around
https://github.com/google/protobuf/issues/4210 via
https://github.com/grpc/grpc/pull/14634.

This is needed to support Ruby 2.5
(https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22555).

Gemfile

@@ -417,8 +417,7 @@ end
 gem 'gitaly-proto', '~> 0.118.1', require: 'gitaly'
 gem 'grpc', '~> 1.15.0'
 
-# Locked until https://github.com/google/protobuf/issues/4210 is closed
-gem 'google-protobuf', '= 3.5.1'
+gem 'google-protobuf', '~> 3.6'
 
 gem 'toml-rb', '~> 1.0.0', require: false
 

Gemfile.lock

@@ -303,7 +303,7 @@ GEM
       mime-types (~> 3.0)
       representable (~> 3.0)
       retriable (>= 2.0, < 4.0)
-    google-protobuf (3.5.1)
+    google-protobuf (3.6.1)
     googleapis-common-protos-types (1.0.2)
       google-protobuf (~> 3.0)
     googleauth (0.6.6)
@@ -1005,7 +1005,7 @@ DEPENDENCIES
   gitlab_omniauth-ldap (~> 2.0.4)
   gon (~> 6.2)
   google-api-client (~> 0.23)
-  google-protobuf (= 3.5.1)
+  google-protobuf (~> 3.6)
   gpgme
   grape (~> 1.1)
   grape-entity (~> 0.7.1)

Gemfile.rails5.lock

@@ -306,7 +306,7 @@ GEM
       mime-types (~> 3.0)
       representable (~> 3.0)
       retriable (>= 2.0, < 4.0)
-    google-protobuf (3.5.1)
+    google-protobuf (3.6.1)
     googleapis-common-protos-types (1.0.2)
       google-protobuf (~> 3.0)
     googleauth (0.6.6)
@@ -1014,7 +1014,7 @@ DEPENDENCIES
   gitlab_omniauth-ldap (~> 2.0.4)
   gon (~> 6.2)
   google-api-client (~> 0.23)
-  google-protobuf (= 3.5.1)
+  google-protobuf (~> 3.6)
   gpgme
   grape (~> 1.1)
   grape-entity (~> 0.7.1)