install java in ${GMSH_LIB} as well

wrappers/java/CMakeLists.txt

@@ -69,6 +69,6 @@ POST_BUILD # do the rest of the command after the build period
   COMMAND ${CMAKE_COMMAND} -E copy
     ${CMAKE_CURRENT_SOURCE_DIR}/WrappingJava/build.xml
     ${CMAKE_CURRENT_BINARY_DIR}/WrappingJava/)
-install(TARGETS WrapGmsh DESTINATION lib OPTIONAL)
+install(TARGETS WrapGmsh DESTINATION ${GMSH_LIB} OPTIONAL)
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/WrappingJava/WrapGmsh.jar
-        DESTINATION lib)
+    DESTINATION ${GMSH_LIB})