Modules compatibility: degradation fields now always present.

There is no need to save these two bits as they are wasted anyway.
Removed NGX_HTTP_DEGRADATION from the signature accordingly.

src/core/ngx_module.h

diff --git a/src/core/ngx_module.h b/src/core/ngx_module.h
index c944746..3ac1e43 100644
--- a/src/core/ngx_module.h
+++ b/src/core/ngx_module.h
@@ -170,11 +170,7 @@
 #define NGX_MODULE_SIGNATURE_26  "0"
 #endif
 
-#if (NGX_HTTP_DEGRADATION)
 #define NGX_MODULE_SIGNATURE_27  "1"
-#else
-#define NGX_MODULE_SIGNATURE_27  "0"
-#endif
 
 #if (NGX_HTTP_X_FORWARDED_FOR)
 #define NGX_MODULE_SIGNATURE_28  "1"

src/http/ngx_http_core_module.h

diff --git a/src/http/ngx_http_core_module.h b/src/http/ngx_http_core_module.h
index 773c215..fb391d7 100644
--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -327,10 +327,8 @@
     unsigned      auto_redirect:1;
 #if (NGX_HTTP_GZIP)
     unsigned      gzip_disable_msie6:2;
-#if (NGX_HTTP_DEGRADATION)
     unsigned      gzip_disable_degradation:2;
 #endif
-#endif
 
     ngx_http_location_tree_node_t   *static_locations;
 #if (NGX_PCRE)