[evolution-data-server] Bug 788371 - Correct reuse of _have_headers in FindSMIME.cmake

[Milan Crha <mcrha src gnome org>]

commit 91e58b7586aa36b06b675de214c5c742f38a336e
Author: Дилян Палаузов <dilyan palauzov aegee org>
Date:   Mon Oct 2 19:49:39 2017 +0200

    Bug 788371 - Correct reuse of _have_headers in FindSMIME.cmake

 cmake/modules/FindSMIME.cmake |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/cmake/modules/FindSMIME.cmake b/cmake/modules/FindSMIME.cmake
index 3f47a65..8f33976 100644
--- a/cmake/modules/FindSMIME.cmake
+++ b/cmake/modules/FindSMIME.cmake
@@ -109,6 +109,8 @@ if(NOT (WITH_NSS_INCLUDES STREQUAL ""))
        set(CMAKE_REQUIRED_INCLUDES ${WITH_NSS_INCLUDES})
 endif(NOT (WITH_NSS_INCLUDES STREQUAL ""))
 
+unset(_have_headers CACHE)
+
 CHECK_INCLUDE_FILES(nss.h ssl.h smime.h _have_headers)
 
 unset(CMAKE_REQUIRED_INCLUDES)