[FEM] [skip CI] fix a string

src/Mod/Fem/femsolver/settings.py

@@ -114,7 +114,7 @@ def get_cores(name):
     if name in _SOLVER_PARAM:
         cores = _SOLVER_PARAM[name].get_cores()
         FreeCAD.Console.PrintMessage(
-            'Number of CPU cores to be used for the solvier run: {} \n'
+            "Number of CPU cores to be used for the solvier run: {} \n"
             .format(cores)
         )
         return cores