update pkg format version

mesh_navigation/package.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<package format="2">
+<package format="3">
     <name>mesh_navigation</name>
     <version>1.0.1</version>
     <description>The mesh_navigation package provides a layered mesh_map implementation, a Move Base Flex mesh navigation server, as well as mesh navigation plugins for path planning and navigation control.</description>