fix git repo URL for mvfst manifest

Summary:
the repo was moved

Created from CodeHub with https://fburl.com/edit-in-codehub

Reviewed By: mjoras, kvtsoy

Differential Revision: D48090468

fbshipit-source-id: 2c94b5a68944530a4604fff8052da30d1754f8fb

build/fbcode_builder/manifests/mvfst

@@ -5,7 +5,7 @@ shipit_project = mvfst
 shipit_fbcode_builder = true
 
 [git]
-repo_url = https://github.com/facebookincubator/mvfst.git
+repo_url = https://github.com/facebook/mvfst.git
 
 [build]
 builder = cmake