Solve the adaptability problem of Windows (#125)

Windows does not support the grep command, so this project cannot use the make command under the Windows environment.

Makefile

@@ -7,7 +7,7 @@ ifeq ($(GOHOSTOS), windows)
 	#to see https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/find.
 	#changed to use git-bash.exe to run find cli or other cli friendly, caused of every developer has a Git.
 	#Git_Bash= $(subst cmd\,bin\bash.exe,$(dir $(shell where git)))
-	Git_Bash=$(subst \,/,$(subst cmd\,bin\bash.exe,$(dir $(shell where git | grep cmd))))
+	Git_Bash=$(subst \,/,$(subst cmd\,bin\bash.exe,$(dir $(shell where git))))
 	INTERNAL_PROTO_FILES=$(shell $(Git_Bash) -c "find internal -name *.proto")
 	API_PROTO_FILES=$(shell $(Git_Bash) -c "find api -name *.proto")
 else