backport fix

doc/man/man5/slapd.access.5

@@ -738,7 +738,7 @@ clause, one could use
 .LP
 .nf
 	access to dn.regex="^(.+,)?uid=([^,]+),dc=example,dc=com$"
-		by dn.regex="^uid=$1,dc=example,dc=com$$" write
+		by dn.regex="^uid=$2,dc=example,dc=com$$" write
 		by ...
 .fi
 .LP
@@ -748,7 +748,7 @@ clause is substring expansion, a more efficient solution is
 .LP
 .nf
 	access to dn.regex="^(.+,)?uid=([^,]+),dc=example,dc=com$"
-		by dn.exact,expand="uid=$1,dc=example,dc=com" write
+		by dn.exact,expand="uid=$2,dc=example,dc=com" write
 		by ...
 .fi
 .LP