Set default z-hop speed to allowed value

resources/definitions/printrbot_play.def.json

@@ -45,6 +45,7 @@
         },
         "machine_end_gcode": {
             "default_value": "M104 S0 ;extruder heater off\nM140 S0 ;heated bed heater off (if you have it)\nG91 ;relative positioning\nG1 E-1 F300  ;retract the filament a bit before lifting the nozzle, to release some of the pressure\nG1 Z+0.5 E-5 X-20 Y-20 F9000 ;move Z up a bit and retract filament even more\nG28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way\nM84 ;steppers off\nG90 ;absolute positioning"
-        }
+        },
+        "speed_z_hop": {"default_value": 5}
     }
 }