Change OVAL version to 5.11.2

The SCAP 1.3 source datastream schema imports OVAL 5.11.2.

Author: jan-cerny

tests/DS/sds_detect_version/scap-1.3-ds.xml

@@ -10,7 +10,7 @@
       <ns4:generator>
         <ns6:product_name>combine_ovals.py from SCAP Security Guide</ns6:product_name>
         <ns6:product_version>ssg: [0, 1, 44], python: 3.7.3</ns6:product_version>
-        <ns6:schema_version>5.11</ns6:schema_version>
+        <ns6:schema_version>5.11.2</ns6:schema_version>
         <ns6:timestamp>2019-05-10T06:18:18</ns6:timestamp>
       </ns4:generator>
       <ns4:definitions>