Replace deprecated git branch parameter "--set-upstream"

From: Andre Rosa <[email protected]>

Since 2017-08-17 (git version 2.14.1.473.g3ec7d702a) using deprecated git branch parameter "--set-upstream" causes a fetcher error. Replace it by "--set-upstream-to".

https://git.kernel.org/pub/scm/git/git.git/commit/?id=52668846ea2d41ffbd87cda7cb8e492dea9f2c4d
says, it's deprecated since 2012-08-30 so hopefully all still supported host distributions have new enough git to support "--set-upstream-to".

ERROR: PACKAGE do_unpack: Fetcher failure: ...;
git -c core.fsyncobjectfiles=0 branch --set-upstream master origin/master failed with exit code 128, output:
fatal: the '--set-upstream' option is no longer supported. Please use '--track' or '--set-upstream-to' instead.

ERROR: PACKAGE do_unpack: Function failed: base_do_unpack

---
 lib/bb/fetch2/git.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 534c93d3..5ef8cd69 100644
@@ -485,7 +485,7 @@ class Git(FetchMethod):
                 branchname =  ud.branches[ud.names[0]]
                 runfetchcmd("%s checkout -B %s %s" % (ud.basecmd, branchname, \
                             ud.revisions[ud.names[0]]), d, workdir=destdir)
-                runfetchcmd("%s branch --set-upstream %s origin/%s" % (ud.basecmd, branchname, \
+                runfetchcmd("%s branch %s --set-upstream-to origin/%s" % (ud.basecmd, branchname, \
                             branchname), d, workdir=destdir)
             else:
                 runfetchcmd("%s checkout %s" % (ud.basecmd, ud.revisions[ud.names[0]]), d, workdir=destdir)

2.14.1