Fix find_package() library variables for libtiff.

The detection of libtiff and its related JPEG support now uses the
correct CMake variables set by the corresponding find_package() scripts.

Old and obsolete values were: TIFF_LIBRARY and JPEG_LIBRARY.
New values are: TIFF_LIBRARIES and JPEG_LIBRARIES.

Thanks to "sameeul" (Sameeul Bashir Samee) for the report and patch.

CMake/3rdparty.cmake

@@ -38,11 +38,11 @@ if(DCMTK_USE_FIND_PACKAGE)
       if(NOT JPEG_FOUND)
         message(STATUS "Info: DCMTK TIFF support will be enabled (but without JPEG)")
         include_directories(${TIFF_INCLUDE_DIR})
-        set(LIBTIFF_LIBS ${TIFF_LIBRARY} ${TIFF_EXTRA_LIBS_STATIC})
+        set(LIBTIFF_LIBS ${TIFF_LIBRARIES} ${TIFF_EXTRA_LIBS_STATIC})
       else()
         message(STATUS "Info: DCMTK TIFF support will be enabled")
         include_directories(${TIFF_INCLUDE_DIR} ${JPEG_INCLUDE_DIR})
-        set(LIBTIFF_LIBS ${TIFF_LIBRARY} ${TIFF_EXTRA_LIBS_STATIC} ${JPEG_LIBRARY})
+        set(LIBTIFF_LIBS ${TIFF_LIBRARIES} ${TIFF_EXTRA_LIBS_STATIC} ${JPEG_LIBRARIES})
       endif()
     endif()
   endif()