mke2fs: clarify mke2fs and mke2fs.conf man pages

Addresses-Debian-Bug: #712429
Addresses-Debian-Bug: #712430

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/misc/mke2fs.conf.5.in b/misc/mke2fs.conf.5.in
index b6df767..0625d0e 100644
--- a/misc/mke2fs.conf.5.in
+++ b/misc/mke2fs.conf.5.in
@@ -11,7 +11,7 @@
 .BR mke2fs (8).  
 It controls the default parameters used by 
 .BR mke2fs (8)
-when it is creating ext2 or ext3 filesystems.
+when it is creating ext2, ext3, or ext4 filesystems.
 .PP
 The
 .I mke2fs.conf