make setargv take an array

for consistentcy with getargv, which returns one

IkiWiki/Plugin/external.pm

@@ -162,8 +162,9 @@ sub getargv ($) { #{{{
 
 sub setargv ($@) { #{{{
 	my $plugin=shift;
+	my $array=shift;
 
-	@ARGV=@_;
+	@ARGV=@$array;
 } #}}}
 
 sub inject ($@) { #{{{

doc/plugins/write/external.mdwn

@@ -54,7 +54,7 @@ stored state, call `getstate("page", "id", "key")`, and to store state,
 call `setstate("page", "id", "key", "value")`.
 
 To access ikiwiki's ARGV array, call `getargv()`. To change its ARGV, call
-`setargv(value)`.
+`setargv(array)`.
 
 ## Notes on function parameters