distutils-r1.eclass: Fix PEP517 + single-impl w/ no scripts

Signed-off-by: Michał Górny <mgorny@gentoo.org>

eclass/distutils-r1.eclass

@@ -1274,7 +1274,10 @@ distutils-r1_python_install() {
 		# are already in scriptdir
 		rm -r "${root}${scriptdir}" || die
 		if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
-			mv "${root}$(python_get_scriptdir)" "${root}${scriptdir}" || die
+			local wrapped_scriptdir=${root}$(python_get_scriptdir)
+			if [[ -d ${wrapped_scriptdir} ]]; then
+				mv "${wrapped_scriptdir}" "${root}${scriptdir}" || die
+			fi
 		fi
 	else
 		local root=${D%/}/_${EPYTHON}