cleanup: fix uninitialized member issue

Coverity warning: divedatapoint::minimum_gas was not initialized
in DivePlannerPointsModel::addStop.

I don't know the meaning of that member variable and therefore
cannot tell if this was a real issue.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

qt-models/diveplannermodel.cpp

@@ -824,6 +824,7 @@ int DivePlannerPointsModel::addStop(int milimeters, int seconds, int cylinderid_
 	point.time = seconds;
 	point.cylinderid = cylinderid;
 	point.setpoint = ccpoint;
+	point.minimum_gas.mbar = 0;
 	point.entered = entered;
 	point.divemode = divemode;
 	point.next = NULL;