WiFiFirmwareUpdater: restore null termination

Author: pennam

libraries/STM32H747_System/examples/WiFiFirmwareUpdater/certificates.h

@@ -5428,6 +5428,6 @@ const unsigned char cacert_pem[] = {
   0x58, 0x6f, 0x73, 0x31, 0x41, 0x6e, 0x58, 0x35, 0x69, 0x49, 0x74, 0x72,
   0x65, 0x47, 0x43, 0x63, 0x3d, 0x0a, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x45,
   0x4e, 0x44, 0x20, 0x43, 0x45, 0x52, 0x54, 0x49, 0x46, 0x49, 0x43, 0x41,
-  0x54, 0x45, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a
+  0x54, 0x45, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a, 0x00
 };
-const unsigned int cacert_pem_len = 65156;
+const unsigned int cacert_pem_len = 65157;