mod_crypto: Fix warnings about signed bit fields.

mod_crypto: Fix warnings about signed bit fields.

The non-zero value for one bit field is -1:

mod_crypto.c|565 col 18| error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
||     ctx->encrypt = 1;
||                  ^ ~
mod_crypto.c|746 col 22| error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
||         ctx->clength = 1;
||                      ^ ~
mod_crypto.c|903 col 35| error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
||                     ctx->seen_eos = 1;
||                                   ^ ~
mod_crypto.c|960 col 22| error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
||         ctx->clength = 1;
||                      ^ ~

Use unsigned bit fields for struct crypto_ctx's members seen_eos, encrypt and clength.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1916299 13f79535-47bb-0310-9956-ffa450edef68