Using eval causes problems when the URL contains an appropriately
escaped ampersand (\&). Dropping eval from the built-in browser
invocation avoids the problem.
Helped-by: Jeff King <peff@peff.net> (test case)
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
