Remove trailing spaces in user name

It's quite easy to make a mistake and add an additional space when configuring
users in the vncserver.users config file. You will then get an error that the
user doesn't exist and it's hard to spot the mistake. Same applies for a space
before the display number.

unix/vncserver/vncsession-start.in

 
 DISPLAY="$1"
 
-USER=`grep "^${DISPLAY}=" "${USERSFILE}" 2>/dev/null | head -1 | cut -d = -f 2-`
+USER=`grep "^ *${DISPLAY}=" "${USERSFILE}" 2>/dev/null | head -1 | cut -d = -f 2- | sed 's/ *$//g'`
 
 if [ -z "${USER}" ]; then
 	echo "No user configured for display ${DISPLAY}" >&2