add error message on unknown step

templates/bot_accounts_add.html

@@ -29,6 +29,10 @@
 			<p>FediBooks was unable to authenticate with {{ session['instance'] }}.</p>
 			<p>Click back to try again. If you believe this is in error, you may <a href="https://github.com/Lynnesbian/FediBooks/issues/new/choose">file a bug report</a>.</p>
 
+			{% else %}
+			<h2 class="thin centred">Error</h2>
+			<p>An unknown error has occurred.</p>
+			
 			{% endif %}
 
 			<div class="container centred">

templates/bot_create.html

@@ -32,6 +32,10 @@
 			<p>FediBooks has successfully authenticated with {{ session['instance'] }}, and your bot is ready to be configured. Click finish to return to the bot management screen.</p>
 			<p>To get your bot working, you need to add at least one account for it to learn from. You can do so by clicking the <i class="fas fa-users"></i> button. To configure settings such as posting frequency and content warnings, click the <i class="fas fa-cog"></i> button.</p>
 
+			{% else %}
+			<h2 class="thin centred">Error</h2>
+			<p>An unknown error has occurred.</p>
+
 			{% endif %}
 
 			<div class="container centred">