Add Http2Origin option to force HTTP/2 origin connections

If `http2Origin` is set, it will set `ForceAttemptHTTP2` in the transport config of the `OriginService`.

config/configuration.go

@@ -227,6 +227,8 @@ type OriginRequestConfig struct {
 	ProxyType *string `yaml:"proxyType" json:"proxyType,omitempty"`
 	// IP rules for the proxy service
 	IPRules []IngressIPRule `yaml:"ipRules" json:"ipRules,omitempty"`
+	// Attempt to connect to origin with HTTP/2
+	Http2Origin *bool `yaml:"http2Origin" json:"http2Origin,omitempty"`
 }
 
 type IngressIPRule struct {

config/configuration_test.go

@@ -139,7 +139,8 @@ var rawConfig = []byte(`
 			"ports": [443, 4443],
 			"allow": true
 		}
-	]
+	],
+	"http2Origin": true
 }
 `)
 
@@ -188,6 +189,7 @@ func assertConfig(
 	assert.Equal(t, true, *config.NoTLSVerify)
 	assert.Equal(t, uint(9000), *config.ProxyPort)
 	assert.Equal(t, "socks", *config.ProxyType)
+	assert.Equal(t, true, *config.Http2Origin)
 
 	privateV4 := "10.0.0.0/8"
 	privateV6 := "fc00::/7"