Update version string in about box to 1.9.1rc1

src/resources/html/about.html

 				<div class="topbanner">
 					<a href="https://typica.us/"><img src="../icons/appicons/logo96.png" height="96px" width="96px" alt="Typica logo" /></a>
 					<h1><a href="https://typica.us/">Typica</a></h1>
-					<h2>Version 1.9.1</h2>
+					<h2>Version 1.9.1rc1</h2>
 				</div>
 			<div id="maintext">
 				<p>Copyright &copy; 2007&ndash;2018 Neal Evan Wilson <a href="mailto:neal@typica.us?subject=Thanks%20for%20Typica&amp;body=Message%20initiated%20from%20Typica.">&lt;neal@typica.us&gt;</a></p>