scm: git: remove "test_getting_certain_revisions" from unit lib test

Redmine does not use '899a15d^' syntax.
This test is covered by "test_revisions_master_merged_rev".

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@8809 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/lib/redmine/scm/adapters/git_adapter_test.rb

@@ -91,10 +91,6 @@ begin
         assert_equal 21, @adapter.revisions('',nil,nil,:all => true).length
       end
 
-      def test_getting_certain_revisions
-        assert_equal 1, @adapter.revisions('','899a15d^','899a15d').length
-      end
-
       def test_revisions_reverse
         revs1 = @adapter.revisions('',nil,nil,{:all => true, :reverse => true })
         assert_equal 21, revs1.length