qf: remove sizetopopup from locator popup (#4846)

This may help with the issue of locator popup sometimes
not being properly rendered.

Also, it allows the popup to have a proper width on
windows when "Always show scrollbar" setting is on.

Addresses: #4814
Addresses: #4805

chrome/content/zotero/integration/quickFormat.xhtml

@@ -97,7 +97,7 @@
 			<description id="citation-properties-info" tabindex="2"/>
 		</vbox>
 		<html:div id="citation-properties-grid">
-			<menulist id="locator-label" sizetopopup="none" tabindex="3"
+			<menulist id="locator-label" tabindex="3"
 					  oncommand="Zotero_QuickFormat.onCitationPropertiesChanged(event)" native="true">
 				<menupopup id="locator-label-popup" onpopuphidden="Zotero_QuickFormat.ignoreEvent(event)"/>
 			</menulist>