Fix reading of cloud tags

Fix reading of cloud tags

The projectroot path could have SP in it, in which case iterating over
<$git_dir/ctags/*> does not correctly enumerate the cloud tags files at
all.

This can be observed by creating an empty t/trash directory and running
t9500 test.  The $projectroot ends with "trash directory.t9500-gitweb-/"
and <$glob> would give "trash", which can be opened and reading from it
immediately yields undef, which in turn gives an undef value warning to
the standard error stream upon attempt to chomp it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>