add lighttpd.exe to the list of processes to kill on the bots
add lighttpd.exe to the list of processes to kill on the bots

this should help prevent stray LigHTTPd processes not shut down during
the layout_tests from causing problems down the road.

R=cmp@chromium.org
BUG=169530


Review URL: https://chromiumcodereview.appspot.com/11880039

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@176770 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build