gdbm: bump to version 1.11 and fix license

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gdbm/gdbm.mk

@@ -4,9 +4,9 @@
 #
 ################################################################################
 
-GDBM_VERSION = 1.10
+GDBM_VERSION = 1.11
 GDBM_SITE = $(BR2_GNU_MIRROR)/gdbm
-GDBM_LICENSE = GPLv3
+GDBM_LICENSE = GPLv3+
 GDBM_LICENSE_FILES = COPYING
 GDBM_INSTALL_STAGING = YES