[buildbot] phase1: initialize source.git on first start

[LEDE Commits]

jow pushed a commit to buildbot.git, branch master:
https://git.lede-project.org/0c3951adfac238bd1ead976bbaf2513e573a1167

commit 0c3951adfac238bd1ead976bbaf2513e573a1167
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Fri Nov 4 15:56:02 2016 +0100

    phase1: initialize source.git on first start
    
    Since phase1 needs an existing source.git to bootstrap its config, prepare
    the git clone further processing.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 phase1/master.cfg | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/phase1/master.cfg b/phase1/master.cfg
index 89243ff..4ff4ced 100644
--- a/phase1/master.cfg
+++ b/phase1/master.cfg
@@ -82,6 +82,9 @@ if ini.has_option("gpg", "passfile"):
 # find targets
 targets = [ ]
 
+if not os.path.isdir(home_dir+'/source.git'):
+	subprocess.call(["git", "clone", "--depth=1", repo_url, home_dir+'/source.git'])
+
 findtargets = subprocess.Popen([home_dir+'/dumpinfo.pl', 'targets'],
 	stdout = subprocess.PIPE, cwd = home_dir+'/source.git')