FEM: Use format to avoid error is the message is not pure string
FEM: Use format to avoid error is the message is not pure string

Traceback (most recent call last):
  File "/home/przemo/software/FreeCAD/build/Mod/Fem/TestFem.py", line
229, in test_new_analysis
    ret = self.compare_stats(fea, static_expected_values)
  File "/home/przemo/software/FreeCAD/build/Mod/Fem/TestFem.py", line
147, in compare_stats
    fcc_print(sf_content)
  File "/home/przemo/software/FreeCAD/build/Mod/Fem/TestFem.py", line
55, in fcc_print
    FreeCAD.Console.PrintMessage(message + '\n')
TypeError: can only concatenate list (not "str") to list

Signed-off-by: Przemo Firszt <ebf2bb805329591a27e694024b5e4c3c5da00121@firszt.eu>

Fat-Zer/FreeCAD_sf_master,maurerpe/FreeCAD,usakhelo/FreeCAD,maurerpe/FreeCAD,chrisjaquet/FreeCAD,maurerpe/FreeCAD,timthelion/FreeCAD,timthelion/FreeCAD,chrisjaquet/FreeCAD,wood-galaxy/FreeCAD,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,timthelion/FreeCAD,bblacey/FreeCAD-MacOS-CI,timthelion/FreeCAD,maurerpe/FreeCAD,usakhelo/FreeCAD,chrisjaquet/FreeCAD,usakhelo/FreeCAD,bblacey/FreeCAD-MacOS-CI,bblacey/FreeCAD-MacOS-CI,usakhelo/FreeCAD,wood-galaxy/FreeCAD,timthelion/FreeCAD,Fat-Zer/FreeCAD_sf_master,usakhelo/FreeCAD,bblacey/FreeCAD-MacOS-CI,Fat-Zer/FreeCAD_sf_master,bblacey/FreeCAD-MacOS-CI,usakhelo/FreeCAD,wood-galaxy/FreeCAD,wood-galaxy/FreeCAD,chrisjaquet/FreeCAD,kkoksvik/FreeCAD,kkoksvik/FreeCAD,wood-galaxy/FreeCAD,timthelion/FreeCAD,kkoksvik/FreeCAD,kkoksvik/FreeCAD,kkoksvik/FreeCAD,chrisjaquet/FreeCAD,chrisjaquet/FreeCAD,bblacey/FreeCAD-MacOS-CI,wood-galaxy/FreeCAD,chrisjaquet/FreeCAD,maurerpe/FreeCAD,usakhelo/FreeCAD,bblacey/FreeCAD-MacOS-CI