Use a dedicated build part for challenge passwords, BUILD_PASSPHRASE gets obsolete

src/libstrongswan/credentials/builder.h

@@ -103,6 +103,8 @@ enum builder_part_t {
 	BUILD_X509_FLAG,
 	/** enumerator_t over (chunk_t serial, time_t date, crl_reason_t reason) */
 	BUILD_REVOKED_ENUMERATOR,
+	/** PKCS#10 challenge password */
+	BUILD_CHALLENGE_PWD,
 	/** friendly name of a PKCS#11 module, null terminated char* */
 	BUILD_PKCS11_MODULE,
 	/** slot specifier for a token in a PKCS#11 module, int */