Indent using spaces, not a mix of tabs and spaces

Contributes to issue CURA-7450.

resources/definitions/smoothie.def.json

@@ -25,7 +25,7 @@
             "default_value": "RepRap (Marlin/Sprinter)"
         },
         "machine_always_write_active_tool": {
-        	"default_value": true
+            "default_value": true
         },
         "machine_start_gcode": {
             "default_value": "G28 X0 Y0 ; Home X Y\nM375; Load Bed Leveling Grid\nG1 X300 Y275 F15000 ; Move to bed center\nM280 S3.0 ; Deploy probe pin\n## NOTE: Adjust \"ZX.XX\" after G30 to be the Z-offset (in mm) between the probe and the nozzle\n## This is how you adjust nozzle printing height!\nG30 Z1.25 ; Move down to find bed & set Z home offset\nM280 S7.0 ; Retract probe\nG1 Z15.0 F600 ; move extruder up 15mm\nT0; Activate Extruder 1"