Fix typos in stackrc and unstack.sh

Componets => Components
pluggins => plugins

Change-Id: I82634a55fd5895599099c94817af7d8d2f602859
diff --git a/unstack.sh b/unstack.sh
index 10e5958..27d6719 100755
--- a/unstack.sh
+++ b/unstack.sh
@@ -45,7 +45,7 @@
 # Configure Projects
 # ==================
 
-# Plugin Phase 0: override_defaults - allow pluggins to override
+# Plugin Phase 0: override_defaults - allow plugins to override
 # defaults before other services are run
 run_phase override_defaults