package/libssh2: fix autoreconf comment

The comment explaining the autoreconf says that we are building from a git
clone - but we are not, currently.  However, the reconf is still needed due
to patches modifying ac files.

This commit corrects the comment.

Signed-off-by: Danomi Manchego <danomimanchego123@gmail.com>
[yann.morin.1998@free.fr: also mention acincludes.m4]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/libssh2/libssh2.mk

@@ -14,7 +14,7 @@ LIBSSH2_CONF_OPTS = --disable-examples-build
 # 0003-packet-c-improve-message-parsing.patch
 LIBSSH2_IGNORE_CVES += CVE-2019-17498
 
-# building from a git clone
+# patch touching configure.ac and acinclude.m4
 LIBSSH2_AUTORECONF = YES
 
 ifeq ($(BR2_PACKAGE_LIBSSH2_MBEDTLS),y)