Add Block::GetBlocks which returns an iterable list of blocks.

modules/rewrite.cpp

@@ -173,10 +173,8 @@ public:
 	{
 		Rewrite::rewrites.clear();
 
-		for (int i = 0; i < conf.CountBlock("command"); ++i)
+		for (const auto &[_,  block] : conf.GetBlocks("command"))
 		{
-			const auto &block = conf.GetBlock("command", i);
-
 			if (!block.Get<bool>("rewrite"))
 				continue;