package/davfs2: fix indent

Fix the following check-package warning added by commit
a2b98a6add92e38dbcd4ca9fda25454a38c719e3:

package/davfs2/davfs2.mk:22: expected indent with tabs

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/davfs2/davfs2.mk

@@ -19,7 +19,7 @@ DAVFS2_CONF_ENV += \
 	LIBS=$(TARGET_NLS_LIBS)
 
 define DAVFS2_USERS
-        davfs2 -1 davfs2 -1 * - - - davfs user
+	davfs2 -1 davfs2 -1 * - - - davfs user
 endef
 
 $(eval $(autotools-package))