fix: empty keys in $rps are deleted

Irpg/Main.pm

@@ -262,6 +262,15 @@ sub rpcheck { # check levels, update database
     # there's really nothing to do here if there are no online users
     return unless $online;
 
+    # Sometimes an empty key is added in $rps
+    # while the origin of this problem is not found,
+    # here is a workaround
+    if (grep { $_ eq '' } keys %$rps) {
+        debug("Error: empty key in \%\$rps. Deleting.");
+        #print(Irpg::Utils::ts()."Error: empty key in \%\$rps. Deleting.");
+        delete $rps->{''};
+    }
+
     ### MOVING PLAYERS ###
     moveplayers();