Remove unused problem filter

This fixes quality gate warning

"The API problem filter for: 'The visibility of the constructor
org.eclipse.pde.core.plugin.PluginRegistry.PluginRegistry() has been
reduced' is no longer used"

ui/org.eclipse.pde.core/.settings/.api_filters

@@ -1,13 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <component id="org.eclipse.pde.core" version="2">
-    <resource path="src/org/eclipse/pde/core/plugin/PluginRegistry.java" type="org.eclipse.pde.core.plugin.PluginRegistry">
-        <filter id="354463860">
-            <message_arguments>
-                <message_argument value="org.eclipse.pde.core.plugin.PluginRegistry"/>
-                <message_argument value="PluginRegistry()"/>
-            </message_arguments>
-        </filter>
-    </resource>
     <resource path="src/org/eclipse/pde/internal/core/project/BundleProjectService.java" type="org.eclipse.pde.internal.core.project.BundleProjectService">
         <filter comment="Platform Team allows use of bundle importers for PDE import from source repository" id="640712815">
             <message_arguments>