Change build-depends to list libssl-dev first. Outcome in sid/buster is to switch to openssl 1.1. I am not changing the soname despite the implied change to the libcurl ABI, because we don't want to make our libcurl have a nonstandard soname.
curl (7.56.1-1) unstable; urgency=medium
* New upstream release
- Fix IMAP FETCH response out of bounds read as per CVE-2017-
1000257
https://curl.haxx.se/docs/adv_20171023.html
* Bump Standards-Version to 4.1.1 (no changes needed)
* Drop 01_runtests_gdb.patch
* Drop 12_dont-wait-on-CONNECT.patch
* Refresh patches
* Update *.symbols files
* Use https:// URL in watch file
[dgit import unpatched curl 7.56.1-1]