Add missing nif target

Author: mischov

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        nif: ["2.15", "2.16"]
+        nif: ["2.14", "2.15", "2.16"]
         job:
           - { target: arm-unknown-linux-gnueabihf , os: ubuntu-20.04 , use-cross: true }
           - { target: aarch64-unknown-linux-gnu   , os: ubuntu-20.04 , use-cross: true }