czmq: drop libpcre dependency

It seems like the libpcre dependency was added by mistake.
While checking in the source code of czmq (Makefile.am, CMakeLists.txt),
I see there are several dependencies, but there isn't PCRE.

Fixes: 936a48a ("czmq: add new package")

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>

libs/czmq/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=czmq
 PKG_VERSION:=4.2.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://github.com/zeromq/czmq/releases/download/v$(PKG_VERSION)/
@@ -30,7 +30,7 @@ define Package/czmq
   TITLE:=CZMQ High-level C binding for ZeroMQ
   URL:=http://czmq.zeromq.org
   ABI_VERSION:=4
-  DEPENDS:=+libzmq +libuuid +libpcre +libmicrohttpd +liblz4 +libcurl
+  DEPENDS:=+libzmq +libuuid +libmicrohttpd +liblz4 +libcurl
 endef
 
 define Package/czmq/description