Installation block does not work

The product should block installing below 10.12 but does not. Fixing
typo.

Author: billwert

packaging/osx/clisdk/Distribution-Template

@@ -6,9 +6,9 @@
     <welcome file="welcome.html" mime-type="text/html" />
     <conclusion file="conclusion.html" mime-type="text/html" />
     <volume-check>
-        <allowed-os-version>
+        <allowed-os-versions>
             <os-version min="10.12" />
-        </allowed-os-version>
+        </allowed-os-versions>
     </volume-check>
     <choices-outline>
         <line choice="{SharedFxComponentId}.pkg" />
@@ -32,4 +32,4 @@
     <pkg-ref id="{HostFxrComponentId}.pkg">{HostFxrComponentId}.pkg</pkg-ref>
     <pkg-ref id="{SharedHostComponentId}.pkg">{SharedHostComponentId}.pkg</pkg-ref>
     <pkg-ref id="{CLISdkComponentId}.pkg">{CLISdkComponentId}.pkg</pkg-ref>
-</installer-gui-script>
+</installer-gui-script>