Logic gate biasing a BJT (again)
Is there any solution?


It looks like the transistor is there to forcibly discharge the capacitor so, swap to an NPN and put emitter to ground and invert the logic signal to the base resistor: -



Benefit - the capacitor will be much more fully discharged to 0 volts as opposed to about 0.7 volts with the PNP circuit.

Adding a diode in parallel with the base - emitter junction of the PNP will indeed protect it but, you'll also immediately charge the capacitor via this diode instead of it being charged by the 1 Mohm resistor.