regen-makefile.sh: remove titan < 6.5.1 code path

Prepare to make osmo-ttcn3-hacks.git work with eclipse-titan 8.0.0,
where "ttcn3_makefilegen -v" does not have a "Product number" anymore.

Fix for:
../regen-makefile.sh: 54: ../regen-makefile.sh: arithmetic expression: expecting primary: " >= 65"

Related: OS#5252
Related: If9fef29ce243be112d3735f0236335197f8f140f
Change-Id: Iec26eafc1ddfa19bc1224f6f2abb7fb35cfc188d
1 file changed