Merge pull request #3497 from sigiesec/fix-cmake-config

Problem: generated ZeroMQConfig.cmake does not work when only static …

builds/cmake/ZeroMQConfig.cmake.in

@@ -19,7 +19,11 @@
 if(NOT TARGET libzmq AND NOT TARGET libzmq-static)
   include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
 
+  if (TARGET libzmq)
     get_target_property(@PROJECT_NAME@_INCLUDE_DIR libzmq INTERFACE_INCLUDE_DIRECTORIES)
     get_target_property(@PROJECT_NAME@_LIBRARY libzmq LOCATION)
+  endif()
+  if (TARGET libzmq-static)
     get_target_property(@PROJECT_NAME@_STATIC_LIBRARY libzmq-static LOCATION)
+  endif()
 endif()