octathingy: tweak external shock mount ring

Octathingy_mount_pcb.scad

@@ -918,7 +918,7 @@ module octa_shock_mount_external_ring(height, radius, corner) {
     for (rot = [0, 90, 180, 270]) {
         // anchors for rubber bands
         rotate([0, 0, rot + 45]) {
-            translate([radius * cos(22.5) + ring_wall + 0.5, -6, 0]) {
+            translate([radius * cos(22.5) + ring_wall + 0.75, -6, 0]) {
                 minkowski() {
                     cube([4 - 2, 12, ring_ext_height]);
                     cylinder(r = 1.5, h = thin_mint, $fn = facets);