Check only for WebGL 1.0, move test to HTML file

Whether to use WebGL 1.0 or 2.0 can only be determined at runtime after
reading project settings, so check for the lower version.

The test is now in the HTML file, so if desired WebGL 2.0 can be
checked early by changing the behaviour there.

misc/dist/html/default.html

@@ -244,9 +244,6 @@ $GODOT_HEAD_INCLUDE
 			var statusMode = 'hidden';
 			var indeterminiateStatusAnimationId = 0;
 
-			setStatusMode('indeterminate');
-			engine.setCanvas(canvas);
-
 			function setStatusMode(mode) {
 
 				if (statusMode === mode || !initializing)
@@ -367,18 +364,27 @@ $GODOT_HEAD_INCLUDE
 				});
 			}
 
-			engine.startGame(BASENAME + '.pck').then(() => {
-				setStatusMode('hidden');
-				initializing = false;
-			}, err => {
+			function displayFailureNotice(err) {
+				var msg = err.message || err;
 				if (DEBUG_ENABLED) {
-					printError(err.message);
-					console.warn(err);
+					printError(msg);
 				}
-				setStatusNotice(err.message);
+				console.error(msg);
+				setStatusNotice(msg);
 				setStatusMode('notice');
 				initializing = false;
-			});
+			};
+
+			if (!Engine.isWebGLAvailable()) {
+				displayFailureNotice("WebGL not available");
+			} else {
+				setStatusMode('indeterminate');
+				engine.setCanvas(canvas);
+				engine.startGame(BASENAME + '.pck').then(() => {
+					setStatusMode('hidden');
+					initializing = false;
+				}, displayFailureNotice);
+			}
 		})();
 	//]]></script>
 </body>