Configuration for CVC4
When upgrading CVC4 to 1.5 (a.k.a the most recent version), the shortcut "cvc4" is not assigned to this version by why3config. This persists even if all other versions of this prover are removed and why3config is re-run. Changing shortcut in the configuration file is not a stable fix since next run of why3config redefines the shortcut.