Don't print quotes on gmx_fatal()

Printing a quote is a complex operation involving file I/O and memory
allocation.  This can fail in a number of ways, including calling
gmx_fatal()...  The simplest way to avoid the possibility of deadlocks
and/or endless loops is to not try anything like that in an error
handler.

Change-Id: Id891f8fe2036d10966a1f2c8b0fcb61dadcec39b