Code style improvement

Co-authored-by: Mark Haslinghuis <mark@numloq.nl>

Author: demvlad

src/graph_spectrum_plot.js

@@ -1568,8 +1568,8 @@ GraphSpectrumPlot._drawMousePosition = function (
           lineWidth
         );
 
-        if (this._spectrumType == SPECTRUM_TYPE.PSD_VS_THROTTLE ||
-            this._spectrumType == SPECTRUM_TYPE.PSD_VS_RPM) {
+        if (this._spectrumType === SPECTRUM_TYPE.PSD_VS_THROTTLE ||
+            this._spectrumType === SPECTRUM_TYPE.PSD_VS_RPM) {
           const label = Math.round(this.getValueFromMatrixFFT(mouseFrequency, vsArgValue)).toString() + "dBm/Hz";
           this._drawAxisLabel(
             canvasCtx,