drop unnecessary executable flag of .gitignore
drop unnecessary executable flag of .gitignore

Change-Id: I9bc0049f01db2c7c7f4f0c4b6e34d2b94da10da6
Signed-off-by: Isaku Yamahata <87b7f730b993ec3947ada6404f19ac98e56bb574@intel.com>

opendaylight/neutron