Remove unused unistd.h header from route_tool.cpp (ros-navigation#5292)

Signed-off-by: Silvio Traversaro <[email protected]>

Author: traversaro

nav2_rviz_plugins/src/route_tool.cpp

@@ -15,7 +15,6 @@
 #include "nav2_rviz_plugins/route_tool.hpp"
 #include <QDesktopServices>
 #include <QUrl>
-#include <unistd.h>
 #include <sys/types.h>
 #include <QFileDialog>
 #include "rviz_common/display_context.hpp"