drop old git_require checks

We've been requiring git-1.7.2 since Oct 2012, so we can safely drop
the individual checks sprinkled throughout the code base for older.

Change-Id: I1737fff7b3f27f475960b0bff9cb300aefd5d108
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/253135
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>

project.py

@@ -3125,9 +3125,6 @@ class Project(object):
           raise TypeError('%s() got an unexpected keyword argument %r'
                           % (name, k))
         if config is not None:
-          if not git_require((1, 7, 2)):
-            raise ValueError('cannot set config on command line for %s()'
-                             % name)
           for k, v in config.items():
             cmdv.append('-c')
             cmdv.append('%s=%s' % (k, v))

subcmds/grep.py

@@ -21,7 +21,7 @@ import sys
 from color import Coloring
 from command import PagedCommand
 from error import GitError
-from git_command import git_require, GitCommand
+from git_command import GitCommand
 
 
 class GrepColoring(Coloring):
@@ -162,7 +162,7 @@ contain a line that matches both expressions:
     out = GrepColoring(self.manifest.manifestProject.config)
 
     cmd_argv = ['grep']
-    if out.is_on and git_require((1, 6, 3)):
+    if out.is_on:
       cmd_argv.append('--color')
     cmd_argv.extend(getattr(opt, 'cmd_argv', []))
 

subcmds/sync.py

@@ -580,8 +580,7 @@ later is required to fix a server side protocol bug.
           project.config.SetString('gc.pruneExpire', 'never')
       gc_gitdirs[project.gitdir] = project.bare_git
 
-    has_dash_c = git_require((1, 7, 2))
-    if multiprocessing and has_dash_c:
+    if multiprocessing:
       cpu_count = multiprocessing.cpu_count()
     else:
       cpu_count = 1