Fix stats being reset when enabling the analysis twice

The stats were reset whenever "setAnalysisEnabledXXX(true)" was called.
Due to this, if the analysis for audio or video was already enabled and
the method was called again the stats were wrongly reset. The stats
should be reset only when the analysis is really started again.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

src/utils/webrtc/analyzers/PeerConnectionAnalyzer.js

@@ -203,6 +203,10 @@ PeerConnectionAnalyzer.prototype = {
 	},
 
 	setAnalysisEnabledAudio(analysisEnabledAudio) {
+		if (this._analysisEnabled.audio === analysisEnabledAudio) {
+			return
+		}
+
 		this._analysisEnabled.audio = analysisEnabledAudio
 
 		if (!analysisEnabledAudio) {
@@ -213,6 +217,10 @@ PeerConnectionAnalyzer.prototype = {
 	},
 
 	setAnalysisEnabledVideo(analysisEnabledVideo) {
+		if (this._analysisEnabled.video === analysisEnabledVideo) {
+			return
+		}
+
 		this._analysisEnabled.video = analysisEnabledVideo
 
 		if (!analysisEnabledVideo) {