iperf3: Fix dependecy conflict with iperf3-ssl

When selecting both iperf3 and iperf3 ssl, there is a problem that
both packages install same binary file.
This patch fixes this issue by adding conflict between those packages.

Signed-off-by: Jakub Raczynski <myszsoda@gmail.com>

net/iperf3/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=iperf
 PKG_VERSION:=3.15
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://downloads.es.net/pub/iperf
@@ -46,6 +46,7 @@ $(call Package/iperf3/default)
   TITLE+= with iperf_auth support
   VARIANT:=ssl
   DEPENDS:=+libopenssl
+  CONFLICTS:=iperf3
 endef
 
 define Package/libiperf3