Fix mac-only -Wstrict-prototypes warnings (#1224)

Author: jeroen

src/kms-message/src/kms_crypto_apple.c

@@ -23,13 +23,13 @@
 
 
 int
-kms_crypto_init ()
+kms_crypto_init (void)
 {
    return 0;
 }
 
 void
-kms_crypto_cleanup ()
+kms_crypto_cleanup (void)
 {
 }