Fix typo in input parameter

Author: willend

mcstas-comps/examples/ISIS/ISIS_LET/ISIS_LET.instr

@@ -35,7 +35,7 @@
 *******************************************************************************/
 
 DEFINE INSTRUMENT ISIS_LET(Ei = 3.7, dE=1.1, Ch3_speed=100, Ch5_speed=200,  Ch2_phase=95000, 
-			   pha_offset=80e-6, string res="HF", string snout = "out", int monitor_on=0, int movable_monitors=0)
+			   pha_offset=80e-6, string res="HF", string snout = "out", int monitors_on=0, int movable_monitors=0)
 
 DECLARE
 %{