community/rustup: bump getrandom crate to fix open64
Fixes error found during 3.19 rebuild: https://build.alpinelinux.org/buildlogs/build-3-19-x86_64/community/rustup/rustup-1.25.2-r3.log
Edited by Celeste
Fixes error found during 3.19 rebuild: https://build.alpinelinux.org/buildlogs/build-3-19-x86_64/community/rustup/rustup-1.25.2-r3.log