new error on production

[akhenakh]

2016/01/21 11:09:34 server.go:1934: http: panic serving 127.0.0.1:54434: interface conversion: interface {} is nil, not *lru.entry
goroutine 1759 [running]:
net/http.(*conn).serve.func1(0x20a60060, 0xb2dac638, 0x13202040)
        /usr/lib/go/src/net/http/server.go:1287 +0x9c
github.com/golang/groupcache/lru.(*Cache).removeElement(0x200edef0, 0x18a560a0)
        /home/akh/dev/go/src/github.com/golang/groupcache/lru/lru.go:108 +0x1a0
github.com/golang/groupcache/lru.(*Cache).RemoveOldest(0x200edef0)
        /home/akh/dev/go/src/github.com/golang/groupcache/lru/lru.go:102 +0x58
github.com/golang/groupcache/lru.(*Cache).Add(0x200edef0, 0x4b55b0, 0x13202058, 0x554968, 0x144f0420)
        /home/akh/dev/go/src/github.com/golang/groupcache/lru/lru.go:69 +0x2b0
main.zimHandler(0xb2dac720, 0x228a6080, 0x115c48c0)
        /home/akh/dev/go/src/github.com/akhenakh/gozim/cmd/gozimhttpd/views.go:56 +0x190
main.makeGzipHandler.func1(0xb2dac720, 0x228a6080, 0x115c48c0)
        /home/akh/dev/go/src/github.com/akhenakh/gozim/cmd/gozimhttpd/gzip.go:26 +0x94
net/http.HandlerFunc.ServeHTTP(0x21beb248, 0xb2dac720, 0x228a6080, 0x115c48c0)
        /usr/lib/go/src/net/http/server.go:1422 +0x34
net/http.(*ServeMux).ServeHTTP(0x1150a7c0, 0xb2dac720, 0x228a6080, 0x115c48c0)
        /usr/lib/go/src/net/http/server.go:1699 +0x164
net/http.serverHandler.ServeHTTP(0x22404340, 0xb2dac720, 0x228a6080, 0x115c48c0)
        /usr/lib/go/src/net/http/server.go:1862 +0x190
net/http.(*conn).serve(0x20a60060)
        /usr/lib/go/src/net/http/server.go:1361 +0xbfc
created by net/http.(*Server).Serve
        /usr/lib/go/src/net/http/server.go:1910 +0x360