Update Volcano.dat

Fixed for dot instead of comma

input_models/ScalingTests/Volcano.dat

@@ -20,7 +20,7 @@ unit_stress      = 1e9
 	dt        = 1e-7	# time step
 	dt_min    = 1e-9	# minimum time step (declare divergence if lower value is attempted)
 	dt_max    = 1e-3	# maximum time step
-	inc_dt    = 0,5		# time step increment per time step (fraction of unit)
+	inc_dt    = 0.5		# time step increment per time step (fraction of unit)
 	CFL       = 0.5		# CFL (Courant-Friedrichs-Lewy) criterion
 	CFLMAX    = 0.8		# CFL criterion for elasticity
 	nstep_ini = 0		# save output for n initial steps