Don't report current text in parser error messages

The values of `yytext` and `yyleng` might not be properly defined when
the error function is called (in particular if the lexer reached EOF).
While this might just cause non-printable characters in the output, it
could actually lead to a crash depending on where `yytext` points.

Closes strongswan/strongswan#346.

src/starter/parser/parser.y

@@ -212,14 +212,7 @@ value:
  */
 static void conf_parser_error(parser_helper_t *ctx, const char *s)
 {
-	char *text = conf_parser_get_text(ctx->scanner);
-	int len = conf_parser_get_leng(ctx->scanner);
-
-	if (len && text[len-1] == '\n')
-	{	/* cut off newline at the end to avoid muti-line log messages */
-		len--;
-	}
-	PARSER_DBG1(ctx, "%s [%.*s]", s, (int)len, text);
+	PARSER_DBG1(ctx, "%s", s);
 }
 
 /**