Error_Assertion: Remove unused function.
Error_Assertion: Remove unused function.

Remove the getAssertionBacktrace() function, which isn't used anywhere.
This function is also a bit misleading, since it doesn't actually return
the backtrace from where the assertion failed.

Rud5G/simplesamlphp,Rud5G/simplesamlphp,Rud5G/simplesamlphp,Rud5G/simplesamlphp