bugfix genjava dir variable settings, fixes #1

cmake/genjava-catkin-api.cmake.em

@@ -2,7 +2,7 @@
 # location of scripts in develspace
   set(GENJAVA_MESSAGE_ARTIFACTS_BIN_DIR "@(CMAKE_CURRENT_SOURCE_DIR)/scripts")
 @[else]@
-  set(GENJAVA_MESSAGE_ARTIFACTS_BIN_DIR "${GENJAVA_DIR}/../../../@(CATKIN_PACKAGE_BIN_DESTINATION)")
+  set(GENJAVA_MESSAGE_ARTIFACTS_BIN_DIR "${genjava_DIR}/../../../@(CATKIN_PACKAGE_BIN_DESTINATION)")
 @[end if]@
 
 set(GENJAVA_MESSAGE_ARTIFACTS_BIN ${GENJAVA_MESSAGE_ARTIFACTS_BIN_DIR}/genjava_message_artifacts)

cmake/genjava-extras.cmake.em

@@ -3,7 +3,7 @@
 set(GENJAVA_BIN_DIR "@(CMAKE_CURRENT_SOURCE_DIR)/scripts")
 @[else]@
 # location of scripts in installspace
-set(GENJAVA_BIN_DIR "${GENJAVA_DIR}/../../../@(CATKIN_PACKAGE_BIN_DESTINATION)")
+set(GENJAVA_BIN_DIR "${genjava_DIR}/../../../@(CATKIN_PACKAGE_BIN_DESTINATION)")
 @[end if]@
 
 set(GENJAVA_BIN ${GENJAVA_BIN_DIR}/genjava_gradle_project.py)