gnu: fenics: Skip extra demo in 'check' phase.

* gnu/packages/simulation.scm (fenics)[arguments]: Add 'curl-curl'
demo to list of demos that require meshes supplied by git-lfs.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/simulation.scm

@@ -648,6 +648,7 @@ (define-public fenics
                  "'lift-drag', \n"
                  "'elastodynamics', \n"
                  "'dg-advection-diffusion', \n"
+                 "'curl-curl', \n"
                  "'contact-vi-tao', \n"
                  "'contact-vi-snes', \n"
                  "'collision-detection', \n"