init: remove straggling boost thread_group code

fanquake · fanquake · commit aa72ffb1c297 · 2021-07-12T21:46:59.000+08:00
boost::thread_group usage was removed in bitcoin#21016.
diff --git a/src/init.h b/src/init.h
@@ -20,9 +20,6 @@ struct NodeContext;
 namespace interfaces {
 struct BlockAndHeaderTipInfo;
 }
-namespace boost {
-class thread_group;
-} // namespace boost
 
 /** Interrupt threads */
 void Interrupt(NodeContext& node);

Original file line number	Diff line number	Diff line change
`@@ -20,9 +20,6 @@ struct NodeContext;`
`20`	`20`	`namespace interfaces {`
`21`	`21`	`struct BlockAndHeaderTipInfo;`
`22`	`22`	`}`
`23`		`-namespace boost {`
`24`		`-class thread_group;`
`25`		`-} // namespace boost`
`26`	`23`
`27`	`24`	`/** Interrupt threads */`
`28`	`25`	`void Interrupt(NodeContext& node);`