Remove undesired assert, it makes pybullet mistakes fail in c++

Shared memory api/pybullet: by default, set joint motors in position PD mode with target 0, to maintain 0 joint angle.
pybullet: allow setJointControlMode(body, link, POSITION_CONTROL,targetPos etc.

examples/SharedMemory/PhysicsClientSharedMemory.cpp

@@ -81,7 +81,6 @@ int PhysicsClientSharedMemory::getNumJoints(int bodyIndex) const
 
 		return bodyJoints->m_jointInfo.size(); 
 	}
-	btAssert(0);
 	return 0;
 	
 }