Add missing namespace and XSD to SpotBugs filter file.
diff --git a/conf/findbugs-exclude-filter.xml b/conf/findbugs-exclude-filter.xml
index 5c9949d..bd13e25 100644
--- a/conf/findbugs-exclude-filter.xml
+++ b/conf/findbugs-exclude-filter.xml
@@ -24,7 +24,7 @@
 <FindBugsFilter

     xmlns="https://github.com/spotbugs/filter/3.0.0"

     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

-    xsi:schemaLocation="https://github.com/spotbugs/filter/3.0.0 https://raw.githubusercontent.com/spotbugs/spotbugs/3.1.0/spotbugs/etc/findbugsfilter.xsd"><!-- N.B. Using wild-card class names so exclusions work regardless of the top-level package -->

+    xsi:schemaLocation="https://github.com/spotbugs/filter/3.0.0 https://raw.githubusercontent.com/spotbugs/spotbugs/3.1.0/spotbugs/etc/findbugsfilter.xsd">

 

   <!--  the javadoc states that the default character encoding is used  -->

   <!--  when converting a string into a byte[]                          -->