The anticollider proximity_script should not raise an error if no proximity_rules have been defined.

site_ansto/instrument/bilby/config/anticollider/anticollider.tcl

@@ -58,6 +58,11 @@ namespace eval ::anticollider {
     set catch_status [ catch {
       variable proximity_rules
 
+      if {[info exists proximity_rules] == 0} {
+        return
+      } elseif {[len $proximity_rules] == 0} {
+        return
+      }
       foreach {m1 m2 mdist} $proximity_rules {
         set final($m1) [SplitReply [$m1]]
         set final($m2) [SplitReply [$m2]]