Heapless soundness fix since 0.6.1 (#791)

Author: korken89

crates/heapless/RUSTSEC-2020-0145.md

@@ -12,7 +12,7 @@ informational = "unsound"
 "heapless::vec::IntoIter::clone" = ["<= 0.6"]
 
 [versions]
-patched = []
+patched = [">= 0.6.1"]
 ```
 
 # Use-after-free when cloning a partially consumed `Vec` iterator