Strip [] from IPv6 addresses for FastCGI.

Fixes #845.

middleware/fastcgi/fastcgi.go

@@ -183,6 +183,10 @@ func (h Handler) buildEnv(r *http.Request, rule Rule, fpath string) (map[string]
 		ip = r.RemoteAddr
 	}
 
+	// Remove [] from IPv6 addresses
+	ip = strings.Replace(ip, "[", "", 1)
+	ip = strings.Replace(ip, "]", "", 1)
+
 	// Split path in preparation for env variables.
 	// Previous rule.canSplit checks ensure this can never be -1.
 	splitPos := rule.splitPos(fpath)

middleware/fastcgi/fastcgi_test.go

@@ -137,7 +137,7 @@ func TestBuildEnv(t *testing.T) {
 	fpath := "/fgci_test.php"
 
 	var envExpected = map[string]string{
-		"REMOTE_ADDR":     "[2b02:1810:4f2d:9400:70ab:f822:be8a:9093]",
+		"REMOTE_ADDR":     "2b02:1810:4f2d:9400:70ab:f822:be8a:9093",
 		"REMOTE_PORT":     "51688",
 		"SERVER_PROTOCOL": "HTTP/1.1",
 		"QUERY_STRING":    "test=blabla",
@@ -150,7 +150,7 @@ func TestBuildEnv(t *testing.T) {
 
 	// 2. Test for shorthand notation of IPv6 address
 	r.RemoteAddr = "[::1]:51688"
-	envExpected["REMOTE_ADDR"] = "[::1]"
+	envExpected["REMOTE_ADDR"] = "::1"
 	testBuildEnv(&r, rule, fpath, envExpected)
 
 	// 3. Test for IPv4 address