fix(omemo): add missing includes for libomemo-c builds

Signed-off-by: Leon Adomaitis <leon@adomaitis.de>

src/omemo/store.h

@@ -6,10 +6,14 @@
  *
  * SPDX-License-Identifier: GPL-3.0-or-later WITH OpenSSL-exception
  */
-#include <signal/signal_protocol.h>
-
 #include "config.h"
 
+#ifdef HAVE_LIBOMEMO_C
+#include <omemo/signal_protocol.h>
+#else
+#include <signal/signal_protocol.h>
+#endif
+
 #define OMEMO_STORE_GROUP_IDENTITY           "identity"
 #define OMEMO_STORE_GROUP_PREKEYS            "prekeys"
 #define OMEMO_STORE_GROUP_SIGNED_PREKEYS     "signed_prekeys"