Fixed typo in new strain softening function

src/module_strain_soften.f90

@@ -30,6 +30,9 @@ logical            :: error_flag
 
 double precision :: fact
 
+! Store input ss_cur value in case no strain softening occurs
+ss_new=ss_cur
+
 ! Apply strain softening/weakening if onset value is positive
 if (ss_onset.gt.0.d0) then
   ! Set type of strain softening/weakening