remove duplicated registration of JSON plugin

build/scripts/layouts.gant

@@ -76,7 +76,6 @@ def layoutFull(String home, String targetDirectory, String patchedDescriptorDir
     "java-impl",
     "java-psi-impl",
     "java-structure-view",
-    "json",
     "jsp-spi",
     "manifest",
     "platform-main",

python/src/META-INF/pycharm-core.xml

@@ -12,7 +12,6 @@
   <xi:include href="/META-INF/RemoteServers.xml" xpointer="xpointer(/idea-plugin/*)">
     <xi:fallback/>
   </xi:include>
-  <xi:include href="/META-INF/JsonPlugin.xml" xpointer="xpointer(/idea-plugin/*)"/>
 
   <application-components>
     <component>