Prevent canvas (main graph) from being selected on long press on mobile browsers (#1801)

* Prevent canvas from being selected on long press on mobile browsers

* Update CHANGELOG.md

CHANGELOG.md

@@ -26,6 +26,7 @@ All notable changes to this project will be documented in this file.
 - UI fix to align footer columns
 - Guests can now use the favicon to toggle additional info about the site bing viewed (such as in public embeds).
 - Fix SecurityError in tracking script when user has blocked all local storage
+- Prevent dashboard graph from being selected when long pressing on the graph in a mobile browser
 
 ### Changed
 - Cache the tracking script for 24 hours

assets/js/dashboard/stats/visitor-graph.js

@@ -385,7 +385,7 @@ class LineGraph extends React.Component {
             { this.samplingNotice() }
             { this.importedNotice() }
           </div>
-          <canvas id="main-graph-canvas" className={'mt-4 ' + extraClass} width="1054" height="342"></canvas>
+          <canvas id="main-graph-canvas" className={'mt-4 select-none ' + extraClass} width="1054" height="342"></canvas>
         </div>
       </div>
     )