Log Message:
notmuch: Update 0.31.2

Changelog:
What's new in notmuch 0.31.2
=========================

Build
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Catch one more occurence of "version" in the build system, which
caused the file to be regenerated in the release tarball.

What's new in notmuch 0.31.1
=========================

Library
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Fix a memory initialization bug in notmuch_database_get_config_list.

Build
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Rename file 'version' to 'version.txt'. The old file name conflicted
with a C++ header for some compilers.

Replace use of coreutils `realpath` in configure.