package/libmicrohttpd: security bump version to 0.9.55

For details refer to release notes:
http://lists.gnu.org/archive/html/info-gnu/2017-05/msg00014.html

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libmicrohttpd/libmicrohttpd.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256	54797f6e763d417627f89f60e4ae0a431dab0523f92f83def23ea02d0defafea	libmicrohttpd-0.9.52.tar.gz
+sha256 0c1cab8dc9f2588bd3076a28f77a7f8de9560cbf2d80e53f9a8696ada80ed0f8  libmicrohttpd-0.9.55.tar.gz

package/libmicrohttpd/libmicrohttpd.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBMICROHTTPD_VERSION = 0.9.52
+LIBMICROHTTPD_VERSION = 0.9.55
 LIBMICROHTTPD_SITE = $(BR2_GNU_MIRROR)/libmicrohttpd
 LIBMICROHTTPD_LICENSE_FILES = COPYING
 LIBMICROHTTPD_INSTALL_STAGING = YES