update missing mc command on multipart-tests

Author: harshavardhana

.github/workflows/multipart/migrate.sh

@@ -28,8 +28,8 @@ docker-compose -f docker-compose-site2.yaml up -d
 
 sleep 30
 
-mc alias set site1 http://site1-nginx:9001 minioadmin minioadmin --api s3v4
-mc alias set site2 http://site2-nginx:9002 minioadmin minioadmin --api s3v4
+./mc alias set site1 http://site1-nginx:9001 minioadmin minioadmin --api s3v4
+./mc alias set site2 http://site2-nginx:9002 minioadmin minioadmin --api s3v4
 
 ./mc ready site1/
 ./mc ready site2/