Do not fire phaser when no Klingon in quadrant

See https://github.com/jj1bdx/erltrek/commit/8282b539ddc7f7bcfc6b6946f84629ac066dec5e and see https://github.com/jj1bdx/erltrek/commit/8282b539ddc7f7bcfc6b6946f84629ac066dec5e#commitcomment-5756681 for the details. Revised for the latest commit.