Get rid of extern declarations of non-existent functions.

Those extern declartions were mistakenly added by commit 7c4f5240.

Author: Petr Jelinek

src/include/replication/logical.h

@@ -95,12 +95,6 @@ extern void DecodingContextFindStartpoint(LogicalDecodingContext *ctx);
 extern bool DecodingContextReady(LogicalDecodingContext *ctx);
 extern void FreeDecodingContext(LogicalDecodingContext *ctx);
 
-extern LogicalDecodingContext *CreateCopyDecodingContext(
-					  List *output_plugin_options,
-					  LogicalOutputPluginWriterPrepareWrite prepare_write,
-					  LogicalOutputPluginWriterWrite do_write);
-extern List *DecodingContextGetTableList(LogicalDecodingContext *ctx);
-
 extern void LogicalIncreaseXminForSlot(XLogRecPtr lsn, TransactionId xmin);
 extern void LogicalIncreaseRestartDecodingForSlot(XLogRecPtr current_lsn,
 									  XLogRecPtr restart_lsn);