tdf#123874: Don't do the SVG preview thing in the iOS app as it crashes WebKit

Sure, this is just a stopgap solution, it would be good to figure out
a way to have the functionality working.
diff --git a/loleaflet/src/layer/tile/TileLayer.js b/loleaflet/src/layer/tile/TileLayer.js
index 726cb62..42c880e 100644
--- a/loleaflet/src/layer/tile/TileLayer.js
+++ b/loleaflet/src/layer/tile/TileLayer.js
@@ -657,7 +657,12 @@
							this._twipsToLatLng(topLeftTwips, this._map.getZoom()),
							this._twipsToLatLng(bottomRightTwips, this._map.getZoom()));
			this._graphicSelectionAngle = (strTwips.length === 5) ? parseInt(strTwips[4]) : 0;
			this._map._socket.sendMessage('rendershapeselection mimetype=image/svg+xml');
			// Workaround for tdf#123874. For some reason the handling of the
			// shapeselectioncontent messages that we get back causes the WebKit process
			// to crash on iOS.
			if (!window.ThisIsTheiOSApp) {
				this._map._socket.sendMessage('rendershapeselection mimetype=image/svg+xml');
			}
		}

		this._onUpdateGraphicSelection();