connect 2D fails with seg fault due to bad imt values

[millerta]

add WARNING or ERROR to connect routines
Check for imt values less than 1

This is a problem when using a parameter that does not have a defined value.
For example see /project/meshing/demos/dfn_dev

define ID
cmo/setatt/cmo/imt ID
connect

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0  0xaec21d in ???
#1  0xaeb893 in ???
#2  0x7f4323536f0f in ???
#3  0x6217ae in connect2d_lg_
	at /project/eesdev/tam/clone/LaGriT/src/connect2d_lg.f:473