fix: remove superfluous BEFORE_COLON in x509_crl.c

BEFORE_COLON and BC defines with the accompanying comment are only
required in x509_crt and x509_csr, but not used in x509_crl.c.

Signed-off-by: Stefan Gloor <[email protected]>
(cherry picked from commit 6a9cf11)

Author: stgloorious

library/x509_crl.c

@@ -583,11 +583,6 @@ int mbedtls_x509_crl_parse_file(mbedtls_x509_crl *chain, const char *path)
 #endif /* MBEDTLS_FS_IO */
 
 #if !defined(MBEDTLS_X509_REMOVE_INFO)
-/*
- * Return an informational string about the certificate.
- */
-#define BEFORE_COLON    14
-#define BC              "14"
 /*
  * Return an informational string about the CRL.
  */