Add text for 0xe8008019 error.

src/errors.h

@@ -168,7 +168,9 @@ static errorcode_to_id_t errorcode_to_id[] = {
 	{ 0xe800009b, "kAMDMCChallengeRequired" },
 	{ 0xe800009c, "kAMDMissingBundleVersionError" },
 
+	// Errors without id->string mapping.
 	{ 0xe8008015, "A valid provisioning profile for this executable was not found."},
+	{ 0xe8008019, "The application does not have a valid signature." },
 };
 
 const int errorcode_to_id_count = sizeof(errorcode_to_id) / sizeof(errorcode_to_id_t);