Bug fix to prevent packet list search not returning

The symptom is that the spinner stays active. When the packet list
search wraps, it mistakenly moves back to packet 1 to resume the
search. But if a display filter is applied, packet 1 may not be
loaded. The search implementation will make a request to the loader to
load packet 1, but the loader ignores it because as far as it's
concerned, the first block of packets have been loaded in their
entirety; they just don't include packet 1 because it doesn't match the
display filter. This procedure repeated indefinitely. The fix is to loop
back to the first packet loaded.

ui/searchpktlist.go

@@ -155,7 +155,7 @@ Loop:
 		// 32, 44, 45, 134, 209,...
 		curPacketNumber, ok = Loader.PacketNumberOrder[curPacketNumber]
 		if !ok {
-			curPacketNumber = 1
+			curPacketNumber = Loader.PacketNumberOrder[0]
 		}
 		Loader.PsmlLoader.Unlock()