(maint) apache unit test failure

I'm making an educated guess that the error log message for puppet 4.7.1 is formatted in a different way from 4.10.4. the end part of the message, "got 'foo'", may not be present in 4.7.1 or is in a different location. this change still captures the important part of the message while allowing tests to pass.

spec/classes/apache_spec.rb

@@ -636,7 +636,7 @@
         it "should fail" do
           expect do
             catalogue
-          end.to raise_error(Puppet::PreformattedError, /Evaluation Error: Error while evaluating a Resource Statement, Class\[Apache\]: parameter 'sendfile' expects a match for Enum\['Off', 'On', 'off', 'on'\], got 'foo'/)
+          end.to raise_error(Puppet::PreformattedError, /Evaluation Error: Error while evaluating a Resource Statement, Class\[Apache\]: parameter 'sendfile' expects a match for Enum\['Off', 'On', 'off', 'on'\]/)
         end
       end
       context "On" do