git: raise hard version to 1.9.1

Debian 7 Wheezy went EOL in May 2018.  We don't need to carry support
for that anymore as there have been 5 major releases since.  Ubuntu
Precise went EOL in Apr 2019 (including the extended support phase).
That means we can bump the required git version from 1.7.9 to 1.9.1.

git-1.7.9 was released in 2012 while git-1.9.1 was released in 2014.
So that shouldn't be a problem either.  And we've been warning people
using git versions older than 1.9.1 for 3 years now that they need to
upgrade.

Change-Id: Ifbbf72f51010b0a944c2785895d1b605333f9146
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/415637
Reviewed-by: Josip Sokcevic <[email protected]>
Tested-by: Mike Frysinger <[email protected]>
Commit-Queue: Mike Frysinger <[email protected]>

project.py

@@ -1145,8 +1145,7 @@ def UploadForReview(
         # This stops git from pushing all reachable annotated tags when
         # push.followTags is configured. Gerrit does not accept any tags
         # pushed to a CL.
-        if git_require((1, 8, 3)):
-            cmd.append("--no-follow-tags")
+        cmd.append("--no-follow-tags")
 
         for push_option in push_options or []:
             cmd.append("-o")
@@ -2565,12 +2564,7 @@ def _RemoteFetch(
             branch = None
         else:
             branch = self.revisionExpr
-        if (
-            not self.manifest.IsMirror
-            and is_sha1
-            and depth
-            and git_require((1, 8, 3))
-        ):
+        if not self.manifest.IsMirror and is_sha1 and depth:
             # Shallow checkout of a specific commit, fetch from that commit and
             # not the heads only as the commit might be deeper in the history.
             spec.append(branch)

requirements.json

@@ -46,16 +46,14 @@
 
   # Supported git versions.
   #
-  # git-1.7.9 is in Ubuntu Precise.
-  # git-1.7.10 is in Debian Wheezy.
   # git-1.9.1 is in Ubuntu Trusty.
   # git-2.1.4 is in Debian Jessie.
   # git-2.7.4 is in Ubuntu Xenial.
   # git-2.11.0 is in Debian Stretch.
   # git-2.17.0 is in Ubuntu Bionic.
   # git-2.20.1 is in Debian Buster.
   "git": {
-    "hard": [1, 7, 9],
+    "hard": [1, 9, 1],
     "soft": [2, 7, 4]
   }
 }