Remove deprecated python3-lang from the RDEPENDS

The python3-lang package was removed as part of the migration to the
json manifest file.  The functionality is now part of core

Signed-off-by: Derek Straka <derek@asterius.io>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-python/recipes-devtools/python/python3-cryptography_2.1.4.bb

@@ -4,7 +4,3 @@ require python-cryptography.inc
 SRC_URI += " \
     file://run-ptest \
 "
-
-RDEPENDS_${PN} += " \
-    ${PYTHON_PN}-lang \
-"