libmicrohttpd: bump to version 0.9.38

Also add hash file.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libmicrohttpd/libmicrohttpd.hash

@@ -0,0 +1,2 @@
+# Locally calculated after checking pgp signature
+sha256	8df2b4dd863c98799a4775a530d905363fbc02fec850af9094da890b28b9e721	libmicrohttpd-0.9.38.tar.gz

package/libmicrohttpd/libmicrohttpd.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBMICROHTTPD_VERSION = 0.9.37
+LIBMICROHTTPD_VERSION = 0.9.38
 LIBMICROHTTPD_SITE = $(BR2_GNU_MIRROR)/libmicrohttpd
 LIBMICROHTTPD_LICENSE_FILES = COPYING
 LIBMICROHTTPD_INSTALL_STAGING = YES