Non-finite coordinate G1 in FCI

[totork]

I encountered a weird behavior when testing the Laplace inversion with PETSC. Running the inversion with all_terms as a flag, I would get an assertion error that G1 is not finite. Taking a closer look into the code

BOUT-dev/src/mesh/coordinates.cxx

Lines 779 to 787 in 9eb94c7

	} else {
	G1_11 = G1_22 = G1_33 = G1_12 = G1_13 = G1_23 =
	G2_11 = G2_22 = G2_33 = G2_12 = G2_13 = G2_23 =
	G3_11 = G3_22 = G3_33 = G3_12 = G3_13 = G3_23 =
	G1 = G2 = G3 = BoutNaN;
	}

We set all the coefficients G1,G2,G3 to Nan, which should then cause a failure in the inversion. I am not sure this is intended, as well as the if statement in

BOUT-dev/src/mesh/coordinates.cxx

Line 675 in 9eb94c7

if (!g11.isFci()) {