Apply suggestions from code review

Co-authored-by: Marc <m@pyc.ac>
Signed-off-by: Marc <m@pyc.ac>

Author: henderkes

caddy/caddy_test.go

@@ -652,8 +652,8 @@ func TestWorkerPHPServerGlobals(t *testing.T) {
 		http.StatusOK,
 		"SCRIPT_NAME: <br>"+
 			"SCRIPT_FILENAME: "+scriptFilename+"<br>"+
-			"PHP_SELF: /en<br>"+
-			"PATH_INFO: /en<br>"+
+			"PHP_SELF: <br>"+
+			"PATH_INFO: <br>"+
 			"DOCUMENT_ROOT: "+documentRoot2+"<br>"+
 			"REQUEST_URI: /server-globals.php/en<br>",
 	)

cgi.go

@@ -215,6 +215,8 @@ func splitCgiPath(fc *frankenPHPContext) {
 		fc.scriptFilename = fc.worker.fileName
 		if strings.HasPrefix(fc.worker.fileName, fc.documentRoot) {
 			fc.scriptName = filepath.ToSlash(strings.TrimPrefix(fc.worker.fileName, fc.documentRoot))
+		} else {
+			fc.pathInfo = ""
 		}
 		return
 	}