If your servos are stalling, then they are not sufficiently specified to do the work they're intended to do. If you cut them off, they will not be able to hold the load.
If that is what you want to do, then you can try:
1) A 1.5A slow-blow fuse.
2) A 1.5A trip-point resettable PTC fuse.
3) A current sensor and a switch/relay of some sort.
The problem with 1) and 2) is that they are not particularly precise, and they are ambient temperature and duty cycle sensitive. Pololu has some nice current sensors for 3) based on the ACS line of Hall effect sensors. Like this one: http://www.pololu.com/product/1185
Read it with a microcontroller, and use a relay or power MOSFET to cut the power.