Log Message:
libsecret: update to 0.18.5.

0.18.5
 * Build fixes
 * Port tests to Python 3 [#761834]
 * Fix textual typos [#763143]
 * Updated translations

0.18.4
 * Multithreading fixes [#756766]
 * Fix memory leaks [#756766]
 * Updated translations

0.18.3
 * Updated translations
 * Documentation fixes

0.18.2
 * Testing fixes
 * Documentation typo [#747654 ...]
 * Build fixes [#743444]
 * Updated transaltions
 * Accomodate libgcrypt 1.6+

0.18.1
 * Testing fix [#726909]