[RFC PATCH 7/9] util: fix warning about variadic macros

lib/string-list.c: In function ?_notmuch_string_list_sort?: lib/string-list.c:81:59: warning: ISO C99 requires rest arguments to be used [enabled by default] lib/message-file.c: In function ?notmuch_message_file_restrict_headersv?: lib/message-file.c:147:90: warning: ISO C99 requires rest argumen

[RFC PATCH 7/9] util: fix warning about variadic macros

lib/string-list.c: In function ‘_notmuch_string_list_sort’: lib/string-list.c:81:59: warning: ISO C99 requires rest arguments to be used [enabled by default] lib/message-file.c: In function ‘notmuch_message_file_restrict_headersv’: lib/message-file.c:147:90: warning: ISO C99 requires rest argumen