[pyqgis] add missing install of __init__.py for modules

Author: 3nids

python/CMakeLists.txt

@@ -325,6 +325,7 @@ FOREACH(module ${PY_MODULES})
     file(READ ${pyfile} CONTENTS)
     file(APPEND ${QGIS_PYTHON_OUTPUT_DIRECTORY}/${module}/__init__.py "${CONTENTS}")
   ENDFOREACH(pyfile)
+  INSTALL(FILES ${QGIS_PYTHON_OUTPUT_DIRECTORY}/${module}/__init__.py DESTINATION "${QGIS_PYTHON_DIR}/${module}")
 
   FILE(GLOB PY_FILES RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} ${module}/*.py)
   INSTALL(FILES ${PY_FILES} DESTINATION "${QGIS_PYTHON_DIR}/${module}")