mariadb: re-enable jemalloc on darwin and fix impurity
mariadb: re-enable jemalloc on darwin and fix impurity

CMake in its usual infinite wisdom searches all over the system for java
and finds the host OSX java and JNI headers. It then decides to build the
connector and fails later on because we didn't actually tell Nix that we
wanted java in scope. So instead, we just tell CMake that we don't want
the jdbc connector. I believe it does the same with GSS, so I disable
that stuff too. None of this should affect Linux, but let me know if it
does somheow.
NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs