Disable -Wshadow on GNU compile as OGR headers have shadowing parameters we can't fix.

src/osgPlugins/ogr/CMakeLists.txt

@@ -4,5 +4,10 @@ SET(TARGET_SRC ReaderWriterOGR.cpp)
 
 SET(TARGET_LIBRARIES_VARS GDAL_LIBRARY )
 
+IF(CMAKE_COMPILER_IS_GNUCXX)
+    # Remove -pedantic flag as it barfs on ffmoeg headers
+   STRING(REGEX REPLACE "-Wshadow" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+ENDIF()
+
 #### end var setup  ###
 SETUP_PLUGIN(ogr)