Merge branch 'cleanup/test-1pnc-do-not-require-umfpack' into 'master'

[test][facet][1pnc] do not require UMFPack

See merge request !2100

test/multidomain/facet/1pnc_1pnc/main.cc

@@ -209,7 +209,7 @@ int main(int argc, char** argv) try
                                                   couplingManager, timeLoop, xOld);
 
     // the linear solver
-    using LinearSolver = UMFPackBackend;
+    using LinearSolver = ILU0BiCGSTABBackend;
     auto linearSolver = std::make_shared<LinearSolver>();
 
     // the non-linear solver

test/multidomain/facet/1pnc_1pnc/params.input

@@ -29,3 +29,6 @@ SolidHeatCapacity = 790
 
 [Vtk]
 OutputName = test_md_facet_1pnc1pnc
+
+[LinearSolver]
+ResidualReduction = 1e-10