fix(t3c): regex for pparam should check end of path (#7741)

According to the comments in the code, we should check if the filename
is ending with specific extensions. Fix the regex to match this
behavior.
Otherwise it prevents t3c from using pparams such as

@plugin=conf_remap.so @pparam=proxy.config.http.cache.required_headers=0

Signed-off-by: Fatih Acar <[email protected]>

cache-config/t3c-check-refs/t3c-check-refs.go

@@ -115,7 +115,7 @@ func checkConfigLine(line string, lineNumber int, filesAdding map[string]struct{
 				// are assumed to be configuration files and are checked that they
 				// exist in the filesystem at the absolute location in the name
 				// or relative to the ATS configuration files directory.
-				m := regexp.MustCompile(`^*(\.config|\.cfg|\.txt|\.yml|\.yaml|\.lua)+`)
+				m := regexp.MustCompile(`^.+(\.config|\.cfg|\.txt|\.yml|\.yaml|\.lua)$`)
 				sa := strings.Split(fields[ii], "=")
 				if len(sa) != 2 && len(sa) != 3 {
 					log.Errorf("malformed @pparam definition in remap.config on line '%d': %v\n", lineNumber, fields)