Hotfix for 1.2.2 (#276)

* Fix the keepalive implement (#265)

* Release 1.2.3

CocoaMQTT.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name        = "CocoaMQTT"
-  s.version     = "1.2.2"
+  s.version     = "1.2.3"
   s.summary     = "MQTT v3.1.1 client library for iOS and OS X written with Swift 5"
   s.homepage    = "https://github.com/emqtt/CocoaMQTT"
   s.license     = { :type => "MIT" }
@@ -12,7 +12,7 @@ Pod::Spec.new do |s|
   s.ios.deployment_target = "9.0"
   s.tvos.deployment_target = "9.0"
   # s.watchos.deployment_target = "2.0"
-  s.source   = { :git => "https://github.com/emqtt/CocoaMQTT.git", :tag => "1.2.2"}
+  s.source   = { :git => "https://github.com/emqtt/CocoaMQTT.git", :tag => "1.2.3"}
   s.source_files = "Source/{*.h}", "Source/*.swift"
   s.dependency "CocoaAsyncSocket", "~> 7.6.3"
 end

Source/CocoaMQTT.swift

@@ -529,9 +529,9 @@ extension CocoaMQTT: CocoaMQTTReaderDelegate {
         }
 
         // keep alive
-        // FIXME: if keepalive == 0 --> not set keekalive timer???
-        if ack == CocoaMQTTConnAck.accept && keepAlive > 0 {
-            self.aliveTimer = CocoaMQTTTimer.every(Double(self.keepAlive / 2 + 1)) { [weak self] in
+        if ack == CocoaMQTTConnAck.accept {
+            let interval = Double(keepAlive <= 0 ? 60: keepAlive)
+            self.aliveTimer = CocoaMQTTTimer.every(interval) { [weak self] in
                 guard let weakSelf = self else {return}
                 if weakSelf.connState == .connected {
                     weakSelf.ping()