adapted test to default problem

tests/unit/TestPDESolver.cpp

@@ -113,7 +113,7 @@ TEST_P(TestLaplace2D, TestRun) {
 
 class TestGaussHat : public TestPDESolver {
 public:
-    TestGaussHat() : TestPDESolver("3x3Square_DirichletBC") {};
+    TestGaussHat() : TestPDESolver("Square_DirichletBC") {};
 };
 
 INSTANTIATE_TEST_CASE_P(TestPDESolver, TestGaussHat, Values(