Fixes language: "following allowing" -> "allowing"

Stops propagation of initially erroneous construct.

Change-Id: I2197de57cbac98e87fb39fa0dca4c691fe5e856f
diff --git a/exercises/sec_groups.sh b/exercises/sec_groups.sh
index 5f8b0a4..2f78e39 100755
--- a/exercises/sec_groups.sh
+++ b/exercises/sec_groups.sh
@@ -13,7 +13,7 @@
 set -o errexit
 
 # Print the commands being run so that we can see the command that triggers
-# an error.  It is also useful for following allowing as the install occurs.
+# an error.  It is also useful for following as the install occurs.
 set -o xtrace