Possible fix for 21, receiving waypoints

diff --git a/TomTom.lua b/TomTom.lua
index 73a2881..236d424 100755
--- a/TomTom.lua
+++ b/TomTom.lua
@@ -637,6 +637,11 @@ function TomTom:CHAT_MSG_ADDON(event, prefix, data, channel, sender)
         title = string.format(L["Waypoint from %s"], sender)
     end

+    m = tonumber(m)
+    f = tonumber(f)
+    x = tonumber(x)
+    y = tonumber(y)
+
     local zoneName = lmd:MapLocalize(m)
     self:AddMFWaypoint(m, f, x, y, {title = title})
     local msg = string.format(L["|cffffff78TomTom|r: Added '%s' (sent from %s) to zone %s"], title, sender, zoneName)