sitl_gazebo: updated submodule
sitl_gazebo: updated submodule

This fixes a HITL bug and uses promise/future instead of sleeping.

mje-nz/PX4-Firmware,dagar/Firmware,PX4/Firmware,dagar/Firmware,krbeverx/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,dagar/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware,dagar/Firmware,dagar/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware