add profanity-specific CAfile

The profanity-internal mechanism to allow connecting to a server isn't
easily portable to cURL. Therefor introduce a profanity-specific CAfile
which is managed individually and will be configured in libcurl calls.

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>

src/config/files.h

@@ -59,6 +59,7 @@
 #define DIR_DATABASE  "database"
 #define DIR_DOWNLOADS "downloads"
 #define DIR_EDITOR    "editor"
+#define DIR_CERTS     "certs"
 
 void files_create_directories(void);