Update training for jetpack (closes fortressforever/fortressforever#345)

maps/ff_training.lua

@@ -190,14 +190,14 @@ stage_info = {
 			},
 			[10] = {
 				stage_type = HORIZONTAL_JUMP,
-				stage_name = "Flamethrower",
+				stage_name = "Jetpack",
 				stage_specific = "Application",
-				stage_checklist = "Flamethrower",
+				stage_checklist = "Jetpack",
 				stage_code = "a_ft",
 				stage_complete = false,
 				stage_class = Player.kPyro,
-				stage_key_text = "Shoot flamethrower:",
-				stage_key = "%+attack%",
+				stage_key_text = "Use jetpack:",
+				stage_key = "%+attack2%",
 				stage_limits = {
 					force_hhconc = false,
 					force_dropconc = false,