Fix installation of custom error handler during context creation in OCaml bindings
Fix installation of custom error handler during context creation in OCaml bindings

This patch fixes a bug detected by valgrind, where a custom error handler
did not get installed correctly.

kyledewey/z3,seahorn/z3,seahorn/z3,kyledewey/z3,seahorn/z3,kyledewey/z3,seahorn/z3,kyledewey/z3,seahorn/z3,kyledewey/z3,kyledewey/z3,seahorn/z3