Don't enforce gitaly request limits for distinct calls

lib/gitlab/gitaly_client.rb

@@ -165,7 +165,13 @@ module Gitlab
 
       return if permitted_call_count <= MAXIMUM_GITALY_CALLS
 
-      raise TooManyInvocationsError.new(call_site, actual_call_count, max_call_count, max_stacks)
+      # We've exceeded the limit, but we may still be in the presence of a non
+      # n+1 but still complex request with many distinct calls. If the maximum
+      # call count is 1 or less that's probably the case.
+      max_count = max_call_count
+      return if max_count <= 1
+
+      raise TooManyInvocationsError.new(call_site, actual_call_count, max_count, max_stacks)
     end
 
     def self.allow_n_plus_1_calls