PCB: don't output fabrication layers, they don't look good.

Parts center positions should be used instead.

ulx3s.kicad_pcb

@@ -64,7 +64,7 @@
     (grid_origin 93.48 113)
     (visible_elements 7FFFFFFF)
     (pcbplotparams
-      (layerselection 0x310fc_ffffffff)
+      (layerselection 0x010fc_ffffffff)
       (usegerberextensions true)
       (usegerberattributes false)
       (usegerberadvancedattributes false)

ulx3s.kicad_pcb-bak

@@ -7308,7 +7308,7 @@
     (tags SOT-23)
     (path /58D51CAD/58D89315)
     (attr smd)
-    (fp_text reference Q1 (at -3.32 -0.366 180) (layer B.SilkS)
+    (fp_text reference Q1 (at -3.32 -0.493 180) (layer B.SilkS)
       (effects (font (size 1 1) (thickness 0.15)) (justify mirror))
     )
     (fp_text value BC857 (at -3.302 4.699 180) (layer B.Fab)
@@ -10751,7 +10751,7 @@
   (gr_text TMS (at 143.63 110.188 90) (layer B.SilkS)
     (effects (font (size 1 1) (thickness 0.25)) (justify mirror))
   )
-  (gr_text RTC (at 168.537 93.188) (layer B.SilkS)
+  (gr_text RTC (at 168.537 93.315) (layer B.SilkS)
     (effects (font (size 1.5 1.5) (thickness 0.3)) (justify mirror))
   )
   (gr_text ULX3S (at 132.327 75.898) (layer F.SilkS)