dante: disable sched_getscheduler() - not implemented in musl

musl doesn't come with an valid implementation of `sched_getscheduler()`;
it simply returns -ENOSYS for it. Without this option (and compile dante
with `sched_getscheduler()` enabled), you will get

    error: serverinit(): sched_getscheduler(2): failed to retrieve current
    cpuscheduling policy: Function not implemented

and dante won't start at all.

Ref: http://lists.alpinelinux.org/alpine-devel/3932.html
Ref: http://lists.alpinelinux.org/alpine-devel/3936.html
Signed-off-by: David Yang <mmyangfl@gmail.com>
[slightly reword commit message]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/network/utils/dante/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dante
 PKG_VERSION:=1.4.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://www.inet.no/dante/files/
@@ -29,7 +29,8 @@ CONFIGURE_ARGS += \
 	--disable-libwrap
 
 CONFIGURE_VARS += \
-	ac_cv_search_pam_start=""
+	ac_cv_search_pam_start="" \
+	ac_cv_func_sched_setscheduler=no
 
 define Build/InstallDev
 	$(INSTALL_DIR) $(1)/usr/include
@@ -49,7 +50,7 @@ Dante is a circuit-level firewall/proxy that can be used to provide convenient
 and secure network connectivity, requiring only that the server Dante runs on
 has external network connectivity. Dante is used daily by Fortune 100 companies
 and large international organizations, either as a standard SOCKS server or as
-a "reverse proxy". 
+a "reverse proxy".
 endef
 
 define Package/libsocks