libevhtp: Fix dependencies not selected when building static library

When libevhtp is added to a package's PKG_BUILD_DEPENDS (i.e. for
seafile-server), libevhtp's target package dependencies are not
automatically selected, in particular libevent2-openssl and
libevent2-pthreads.

Moreover, if libevent-openssl and libevent2-pthreads are not selected,
OpenSSL and thread support are disabled when compiling libevent2, which
in turn causes a compile error when building libevhtp.

This adds a config option, LIBEVHTP_BUILD_DEPENDS, that will select
libevent2-openssl and libevent2-pthreads (via LIBEVHTP_BUILD_SELECT)
when it is selected.

Other build dependencies are moved to PKG_BUILD_DEPENDS.

This also updates seafile-server to remove the (indirect) dependencies
added in 13d843fec1 and instead select
LIBEVHTP_BUILD_DEPENDS.

This also updates the maintainer's email address and adds myself as
another maintainer.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

net/seafile-server/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=seafile-server
 PKG_VERSION:=7.1.3
-PKG_RELEASE:=3
+PKG_RELEASE:=4
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://codeload.github.com/haiwen/seafile-server/tar.gz/v$(PKG_VERSION)-server?
@@ -20,7 +20,7 @@ PKG_LICENSE:=AGPL-3.0-only
 PKG_LICENSE_FILES:=LICENSE.txt
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)-server
-PKG_BUILD_DEPENDS:=vala/host libevent2 libevent2-openssl libevent2-pthreads libevhtp
+PKG_BUILD_DEPENDS:=vala/host libevhtp
 
 PKG_FIXUP:=autoreconf
 PKG_BUILD_PARALLEL:=1
@@ -52,7 +52,6 @@ define Package/seafile-server
     +libarchive \
     +libevent2 \
     +libevent2-openssl \
-    +libevent2-pthreads \
     +libmariadb \
     +libopenssl \
     +libpthread \
@@ -76,6 +75,10 @@ define Package/seafile-server/description
   protection and teamwork.
 endef
 
+define Package/seafile-server/config
+  select LIBEVHTP_BUILD_DEPENDS
+endef
+
 define Package/seafile-server-fuse
   SECTION:=net
   CATEGORY:=Network
@@ -87,7 +90,6 @@ define Package/seafile-server-fuse
     +jansson \
     +libevent2 \
     +libevent2-openssl \
-    +libevent2-pthreads \
     +libfuse \
     +libmariadb \
     +libopenssl \