Panic when fzf was built without version information

So that the package maintainers would immediately know that the build is
incorrect. But is there a way to make build simply fail?

Related: https://github.com/junegunn/fzf.vim/issues/1150

main.go

@@ -9,6 +9,9 @@ var version string
 var revision string
 
 func main() {
+	if len(version) == 0 {
+		panic("Invalid build: version information missing")
+	}
 	protector.Protect()
 	fzf.Run(fzf.ParseOptions(), version, revision)
 }