+ release.sh: add armv5 build

Close #1239

Squashed commit of the following:

commit 707e2f8e265e294c7b1328c375648f799a5ae293
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Fri Jan 10 16:32:52 2020 +0300

    leave "AdGuardHome_linux_arm" by default

commit cca01fd03200e70d6ee2201540570382f2b7fdf4
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Fri Jan 10 14:53:37 2020 +0300

    fix auto-update; update readme

commit f393a4f511861ef1998c68775bb8f234c5ce1838
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Fri Jan 10 13:00:37 2020 +0300

    + release.sh: add armv5 build; rename armv6 build

commit 73f2d20ba6b0a94a9929882fe15175ba80b528d7
Author: Simon Zolin <s.zolin@adguard.com>
Date:   Fri Jan 10 12:59:55 2020 +0300

    * release.sh: fix indentation

home/control_update.go

@@ -42,7 +42,11 @@ func getVersionResp(data []byte) []byte {
 		return []byte{}
 	}
 
-	_, ok := versionJSON[fmt.Sprintf("download_%s_%s", runtime.GOOS, runtime.GOARCH)]
+	dloadName := fmt.Sprintf("download_%s_%s", runtime.GOOS, runtime.GOARCH)
+	if runtime.GOARCH == "arm" && ARMVersion != "6" {
+		dloadName = fmt.Sprintf("download_%s_%sv%s", runtime.GOOS, runtime.GOARCH, ARMVersion)
+	}
+	_, ok := versionJSON[dloadName]
 	if ok && ret["new_version"] != versionString && versionString >= selfUpdateMinVersion {
 		ret["can_autoupdate"] = true
 	}

home/home.go

@@ -42,6 +42,7 @@ var (
 	versionString   string
 	updateChannel   string
 	versionCheckURL string
+	ARMVersion      string
 )
 
 const versionCheckPeriod = time.Hour * 8
@@ -64,10 +65,11 @@ type homeContext struct {
 var Context homeContext
 
 // Main is the entry point
-func Main(version string, channel string) {
+func Main(version string, channel string, armVer string) {
 	// Init update-related global variables
 	versionString = version
 	updateChannel = channel
+	ARMVersion = armVer
 	versionCheckURL = "https://static.adguard.com/adguardhome/" + updateChannel + "/version.json"
 
 	// config can be specified, which reads options from there, but other command line flags have to override config values