pkp/pkp-lib#8592 Re-executed migration in order to ensure that new 3.…

…4 installations have the proper nullability

dbscripts/xml/upgrade.xml

@@ -116,6 +116,11 @@
 		<migration class="PKP\migration\upgrade\v3_4_0\I9830_FixEmptyUserLocales" />
 	</upgrade>
 
+	<upgrade minversion="3.4.0.0" maxversion="3.4.0.5">
+		<!-- Only new 3.4 installations need this fix -->
+		<migration class="PKP\migration\upgrade\v3_4_0\I8592_SiteNotificationSubscriptions"/>
+	</upgrade>
+
 	<!-- update plugin configuration - should be done as the final upgrade task -->
 	<code function="addPluginVersions" />
 </install>