phosphor-ipmi-config: Handle an empty commit number

The VERSION_ID may not have a commit number for the cases a tag
is created, ex: 2.10.1. Since the code is expecting a commit
number of 1-4 digits, use a '0' if no commit number exists.

Tested: Created a tag 2.10.99 which sets VERSION_ID=2.10.99.
        Without this change, build fails with:
        "Exception: IndexError: list index out of range"
        With this change there are no build errors.

Change-Id: I3b56ebc1844ec6748b92cca3484f9aa1f4d983f8
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/meta-ibm/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend b/meta-ibm/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
index e3e5002..7898a10 100644
--- a/meta-ibm/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
+++ b/meta-ibm/recipes-phosphor/ipmi/phosphor-ipmi-config.bbappend
@@ -22,14 +22,18 @@
     from shutil import copyfile
     version_id = do_get_version(d)
 
-    # count from the commit version
+    # count from the commit version, minimum of one digit
     count = re.findall("-(\d{1,4})-", version_id)
+    if count:
+        commit = count[0]
+    else:
+        commit = "0"
 
     release = re.findall("-r(\d{1,4})", version_id)
     if release:
-        auxVer = count[0] + "{0:0>4}".format(release[0])
+        auxVer = commit + "{0:0>4}".format(release[0])
     else:
-        auxVer = count[0] + "0000"
+        auxVer = commit + "0000"
 
     workdir = d.getVar('WORKDIR', True)
     file = os.path.join(workdir, 'dev_id.json')