Autotools: fixed parsing var assignment without space before =

Parser worked correctly with 'bin_PROGRAMS =', but failed on
'bin_PROGRAMS='. To reproduce problem on Ubuntu, perform 'apt-get source
gentoo' and open Makefile.am in downloaded folder as project: it will be
empty before this change.

Change-Id: I71d0866a2b9d8228ad5ac9237fa34be14b9e9b38
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: hjk <hjk121@nokiamail.com>