Update proto file and fix protoc version parsing

The new protoc cli return version v23.1,
so we parse the file version v4.23.1 without "4."

proxy/loopback/config.pb.go

@@ -1,7 +1,7 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
-// 	protoc        v3.21.12
+// 	protoc-gen-go v1.30.0
+// 	protoc        v4.23.1
 // source: proxy/loopback/config.proto
 
 package loopback