Fix unreadable text in plugin manager (fix #16516)

Author: nyalldawson

src/ui/qgspluginmanagerbase.ui

@@ -37,7 +37,7 @@
      <property name="childrenCollapsible">
       <bool>false</bool>
      </property>
-     <widget class="QFrame" name="mPluginsTabFrame">
+     <widget class="QFrame" name="mOptionsListFrame">
       <property name="sizePolicy">
        <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
         <horstretch>0</horstretch>