cvsserver: Abort if connect to database fails

Currently all calls to the database backend make no
error checking or handling at all. At least abort
if the connection to the database failed since
there is really no way we could do anything useful
after that.

Signed-off-by: Frank Lichtenheld <frank@lichtenheld.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-cvsserver.perl

@@ -2168,6 +2168,7 @@ sub new
     $self->{dbh} = DBI->connect("$self->{dbdriver}:dbname=$self->{dbname}",
                                 $self->{dbuser},
                                 $self->{dbpass});
+    die "Error connecting to database\n" unless defined $self->{dbh};
 
     $self->{tables} = {};
     foreach my $table ( $self->{dbh}->tables )