meson: add missing dots for build options

Most of our Meson build options end with a trailing dot, but those for
our SHA1 and SHA256 backends don't. Add it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

meson_options.txt

@@ -50,9 +50,9 @@ option('regex', type: 'feature', value: 'auto',
 option('https_backend', type: 'combo', value: 'auto', choices: ['auto', 'openssl', 'CommonCrypto', 'none'],
   description: 'The HTTPS backend to use when connecting to remotes.')
 option('sha1_backend', type: 'combo', choices: ['openssl', 'block', 'sha1dc', 'CommonCrypto'], value: 'sha1dc',
-  description: 'The backend used for hashing objects with the SHA1 object format')
+  description: 'The backend used for hashing objects with the SHA1 object format.')
 option('sha256_backend', type: 'combo', choices: ['openssl', 'nettle', 'gcrypt', 'block'], value: 'block',
-  description: 'The backend used for hashing objects with the SHA256 object format')
+  description: 'The backend used for hashing objects with the SHA256 object format.')
 
 # Build tweaks.
 option('macos_use_homebrew_gettext', type: 'boolean', value: true,