protobuf: Update to 3.8.0

Small Makefile cleanups.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/protobuf/Makefile

@@ -8,18 +8,18 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=protobuf
-PKG_VERSION:=3.7.1
+PKG_VERSION:=3.8.0
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-cpp-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://github.com/google/protobuf/releases/download/v$(PKG_VERSION)
-PKG_HASH:=97f6cdaa0724d5a8cd3375d5f5cf4bd253d5ad5291154f533ed0d94a9d501ef3
+PKG_HASH:=ddc96d83f3b7417da53bce2510b94ad2796465ef8763f7a4e82089157efe97aa
 
+PKG_MAINTAINER:=Ken Keys <kkeys@caida.org>
 PKG_LICENSE:=BSD-3-Clause
 PKG_LICENSE_FILES:=LICENSE
 
 PKG_BUILD_DEPENDS:=protobuf/host
-
 PKG_BUILD_PARALLEL:=1
 PKG_INSTALL:=1
 
@@ -32,7 +32,6 @@ define Package/protobuf/Default
   TITLE:=A structured data encoding library
   URL:=https://github.com/google/protobuf
   DEPENDS:=+zlib +libpthread +libatomic +libstdcpp
-  MAINTAINER:=Ken Keys <kkeys@caida.org>
 endef
 
 define Package/protobuf