estrip: Fix handling slashes in STRIP_MASK

Fixes: 244a62a4f275 ("Fix uses of D/ED to account for no trailing slash")
diff --git a/bin/estrip b/bin/estrip
index 41686aa..030d9e8 100755
--- a/bin/estrip
+++ b/bin/estrip
@@ -395,7 +395,7 @@
 		set -o noglob
 		strip_this=true
 		for m in $(eval echo ${STRIP_MASK}) ; do
-			[[ /${x#${ED%/}} == ${m} ]] && strip_this=false && break
+			[[ ${x#${ED%/}} == ${m} ]] && strip_this=false && break
 		done
 		set +o noglob
 	fi