Improved access log escaping to better protect other software.

Some character sets (notably ISO-8859-1) have C1 control characters in
upper half, make sure to escape them.

Reported by Jesus Olmos Gonzalez.
diff --git a/src/http/modules/ngx_http_log_module.c b/src/http/modules/ngx_http_log_module.c
index 9728d54..da6fbb6 100644
--- a/src/http/modules/ngx_http_log_module.c
+++ b/src/http/modules/ngx_http_log_module.c
@@ -690,12 +690,12 @@
         0x10000000, /* 0001 0000 0000 0000  0000 0000 0000 0000 */
 
                     /*  ~}| {zyx wvut srqp  onml kjih gfed cba` */
-        0x00000000, /* 0000 0000 0000 0000  0000 0000 0000 0000 */
+        0x80000000, /* 1000 0000 0000 0000  0000 0000 0000 0000 */
 
-        0x00000000, /* 0000 0000 0000 0000  0000 0000 0000 0000 */
-        0x00000000, /* 0000 0000 0000 0000  0000 0000 0000 0000 */
-        0x00000000, /* 0000 0000 0000 0000  0000 0000 0000 0000 */
-        0x00000000, /* 0000 0000 0000 0000  0000 0000 0000 0000 */
+        0xffffffff, /* 1111 1111 1111 1111  1111 1111 1111 1111 */
+        0xffffffff, /* 1111 1111 1111 1111  1111 1111 1111 1111 */
+        0xffffffff, /* 1111 1111 1111 1111  1111 1111 1111 1111 */
+        0xffffffff, /* 1111 1111 1111 1111  1111 1111 1111 1111 */
     };