remove wrong default value

Author: iychoi

utils/icommands/environment_raw.go

@@ -56,7 +56,7 @@ func CreateICommandsEnvironmentFromFile(envPath string) (*ICommandsEnvironment,
 
 func getDefaultICommandsEnvironment() *ICommandsEnvironment {
 	return &ICommandsEnvironment{
-		AuthenticationFile:      ".irodsA",
+		AuthenticationFile:      "",
 		Port:                    1247,
 		AuthenticationScheme:    "native",
 		ClientServerNegotiation: "", // don't perform negotiation