some http clients say "Content-Encoding: identity" instead of
"Content-Encoding: */*".

Reference: /n/atom/patch/applied2013/httpdacceptany
Date: Wed Jun 19 15:22:32 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/libhttpd/checkcontent.c	Wed Jun 19 15:21:23 2013
+++ /sys/src/libhttpd/checkcontent.c	Wed Jun 19 15:21:23 2013
@@ -3,6 +3,17 @@
 #include <bin.h>
 #include <httpd.h>
 
+static int
+acceptany(char *s, char *list)
+{
+	if(strcmp(s, "*") == 0)
+		return 1;
+	if(cistrcmp(list, "Content-Encoding") == 0)
+	if(cistrcmp(s, "identity") == 0)
+		return 1;
+	return 0;
+}
+
 int
 hcheckcontent(HContent *me, HContent *oks, char *list, int size)
 {
@@ -11,7 +22,7 @@
 	if(oks == nil || me == nil)
 		return 1;
 	for(ok = oks; ok != nil; ok = ok->next){
-		if((cistrcmp(ok->generic, me->generic) == 0 || strcmp(ok->generic, "*") == 0)
+		if((cistrcmp(ok->generic, me->generic) == 0 || acceptany(ok->generic, list))
 		&& (me->specific == nil || cistrcmp(ok->specific, me->specific) == 0 || strcmp(ok->specific, "*") == 0)){
 			if(ok->mxb > 0 && size > ok->mxb)
 				return 0;
@@ -19,7 +30,6 @@
 		}
 	}
 
-	USED(list);
 	if(0){
 		fprint(2, "list: %s/%s not found\n", me->generic, me->specific);
 		for(; oks != nil; oks = oks->next){