Removes the .git folder from .dockerignore.
Removes the .git folder from .dockerignore.

Dockerignoring the .git folder was causing the commit hash be 0000000000

Change-Id: Ic6b8524221943cc456b3fd18c820e41c33cba6e4
(cherry picked from commit ed7dfa6ee7fe69a2a73f5c8608532ef9c469be75)

opennetworkinglab/onos,gkatsikas/onos,gkatsikas/onos,gkatsikas/onos,gkatsikas/onos,opennetworkinglab/onos,opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos,opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos