Disable addition of RPATH to the generated libraries

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Index: b/SConstruct
===================================================================
--- a/SConstruct
+++ b/SConstruct
@@ -273,8 +273,6 @@
     env.Prepend(LIBPATH=[installdir('libdir')])
 else:
     env.Prepend(LIBPATH=[env["sysroot"] + installdir('libdir')])
-if env["shared"]:
-    env.Prepend(RPATH=[installdir('libdir')])
 
 # Give deheader a way to set compiler flags
 if 'MORECFLAGS' in os.environ: