Ignore local.conf in root of repo

gitignore is not parsing regex, only shell globs,
so '^' has no meaning, and local.conf is being thus tracked.

This patch properly ignores only local.conf in root of repo but still
tracks samples/local.conf and others.

Change-Id: I93ef778f1f3ee8101ce21cce377f7b527b7153f3

Author: pshchelo

.gitignore

@@ -28,7 +28,7 @@ files/get-pip.py*
 files/ir-deploy*
 files/ironic-inspector*
 files/etcd*
-^local.conf
+/local.conf
 local.sh
 localrc
 proto