FEM: elmer, add electrostatic equation

src/Mod/Fem/femsolver/elmer/solver.py

@@ -34,6 +34,7 @@ from . import tasks
 
 from .equations import heat
 from .equations import elasticity
+from .equations import electrostatic
 from .equations import flow
 
 
@@ -50,6 +51,7 @@ class Proxy(solverbase.Proxy):
     _EQUATIONS = {
         "Heat": heat,
         "Elasticity": elasticity,
+        "Electrostatic": electrostatic,
         "Flow": flow,
     }