Unify phrases (Recent Activities -> Recent Activity)

ref https://www.woltlab.com/community/thread/312730-language-unify-recent-activity-phrases/

Author: BurntimeX

com.woltlab.wcf/box.xml

@@ -3,7 +3,7 @@
 	<import>
 		<box identifier="com.woltlab.wcf.RecentActivity">
 			<name language="de">Letzte Aktivitäten</name>
-			<name language="en">Recent Activities</name>
+			<name language="en">Recent Activity</name>
 			<boxType>system</boxType>
 			<position>contentBottom</position>
 			<objectType>com.woltlab.wcf.recentActivityList</objectType>
@@ -16,7 +16,7 @@
 				<title>Letzte Aktivitäten</title>
 			</content>
 			<content language="en">
-				<title>Recent Activities</title>
+				<title>Recent Activity</title>
 			</content>
 		</box>
 		<box identifier="com.woltlab.wcf.RegisterButton">

com.woltlab.wcf/menuItem.xml

@@ -34,7 +34,7 @@
 		<item identifier="com.woltlab.wcf.RecentActivityList">
 			<parent>com.woltlab.wcf.MembersList</parent>
 			<title language="de">Letzte Aktivitäten</title>
-			<title language="en">Recent Activities</title>
+			<title language="en">Recent Activity</title>
 			<page>com.woltlab.wcf.RecentActivityList</page>
 		</item>
 		<item identifier="com.woltlab.wcf.UsersOnlineList">

com.woltlab.wcf/page.xml

@@ -20,10 +20,10 @@
 			<pageType>system</pageType>
 			<controller>wcf\page\RecentActivityListPage</controller>
 			<name language="de">Letzte Aktivitäten</name>
-			<name language="en">Recent Activities</name>
+			<name language="en">Recent Activity</name>
 			<parent>com.woltlab.wcf.MembersList</parent>
 			<content language="en">
-				<title>Recent Activities</title>
+				<title>Recent Activity</title>
 			</content>
 			<content language="de">
 				<title>Letzte Aktivitäten</title>

wcfsetup/install/lang/en.xml

@@ -5143,7 +5143,7 @@ You also received a list of backup codes to use when your second factor becomes
 		<item name="wcf.user.usersOnline.sortField.username"><![CDATA[Username]]></item>
 	</category>
 	<category name="wcf.user.recentActivity">
-		<item name="wcf.user.recentActivity"><![CDATA[Recent Activities]]></item>
+		<item name="wcf.user.recentActivity"><![CDATA[Recent Activity]]></item>
 		<item name="wcf.user.recentActivity.more"><![CDATA[Display More]]></item>
 		<item name="wcf.user.recentActivity.noMoreEntries"><![CDATA[There are no new activities at the moment.]]></item>
 		<item name="wcf.user.recentActivity.noEntries"><![CDATA[There are no activities at the moment.]]></item>