changes in Caddy caused mw/root tests to fail:...

changes in Caddy caused mw/root tests to fail: https://github.com/mholt/caddy/commit/4cce8c7b6bf08ffff5e30999aa49259324d58f5d (#990)

middleware/root/root_test.go

@@ -18,7 +18,7 @@ func TestRoot(t *testing.T) {
 	log.SetOutput(ioutil.Discard)
 
 	// Predefined error substrings
-	parseErrContent := "Parse error:"
+	parseErrContent := "Error during parsing:"
 	unableToAccessErrContent := "unable to access root path"
 
 	existingDirPath, err := getTempDirPath()