SSI: avoid potential buffer overflow. When "-" follows a parameter of maximum length, a single byte buffer overflow happens, since the error branch does not check parameter length. Fix is to avoid saving "-" to the parameter key, and instead use an error message with "-" explicitly written. The message is mostly identical to one used in similar cases in the preequal state. Reported by Patrick Wollgast.

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


have=NGX_SUPPRESS_WARN . auto/have

have=NGX_SMP . auto/have