Fixed regex captures handling without PCRE. If PCRE is disabled, captures were treated as normal variables in ngx_http_script_compile(), while code calculating flushes array length in ngx_http_compile_complex_value() did not account captures as variables. This could lead to write outside of the array boundary when setting last element to -1. Found with AddressSanitizer.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  0
#endif

END