Fix GAP interface printing

[rlmill]

I might be wrong, but it looks like output isn't getting printed:

# From a pure GAP session:
GAP4, Version: 4.4.10 of 02-Oct-2007, i686-apple-darwin9.2.2-gcc
gap> g := Group((1,3,2),(2,4,3));
Group([ (1,3,2), (2,4,3) ])
gap> Stabilizer(g,4);
Group([ (1,3,2) ])
gap> 

# From a Sage session:
sage: %gap

  --> Switching to Gap <-- 

''
gap: g := Group((1,3,2),(2,4,3));

gap: Stabilizer(g,4);

gap: 

Component: interfaces

Issue created by migration from https://trac.sagemath.org/ticket/3268

[rlmill]

comment:2

This isn't just for Stabilizer(), since the group isn't printing either...

[mwhansen]

Attachment: trac_3268.patch.gz

[mwhansen]

comment:3

Note that there is no good way to test this as you can't access the processed line as it's completely internal to the function.

[robertwb]

comment:4

Nice catch.