AP_NavEKF3: apply height innovation floor only when barometer is in use

libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp

@@ -608,7 +608,7 @@ void NavEKF3_core::FuseVelPosNED()
                     const float gndMaxBaroErr = 4.0f;
                     const float gndBaroInnovFloor = -0.5f;
 
-                    if(getTouchdownExpected()) {
+                    if(getTouchdownExpected() && activeHgtSource == HGT_SOURCE_BARO) {
                         // when a touchdown is expected, floor the barometer innovation at gndBaroInnovFloor
                         // constrain the correction between 0 and gndBaroInnovFloor+gndMaxBaroErr
                         // this function looks like this: