Use ASSQ instead of ASSOC in GET-HEADER

scheme/httpd/surflets/surflets.scm

@@ -83,7 +83,7 @@
     (release-lock *cache-lock*)
     result))
 
-(define get-header assoc)
+(define get-header assq)
    
 ;; Will be needed when we handle POST requests.
 (define (get-content-length headers)