Resolved warning on raise_error without specifying error in mind.

Author: jgebal

spec/plsql/procedure_spec.rb

@@ -1872,7 +1872,7 @@ def new_candidate(status)
       expect(plsql.test_cursor do |cursor|
         cursor2 = cursor
       end).to be_nil
-      expect { cursor2.fetch }.to raise_error
+      expect { cursor2.fetch }.to raise_error(/Cursor was already closed/)
     end
 
     it "should not raise error if cursor is closed inside block" do