Update FindBugs Maven plugin from 3.0.1 to 3.0.5

Fixes build with Maven 3.6.x. The error message was

    [ERROR] Failed to execute goal org.codehaus.mojo:findbugs-maven-plug
    in:3.0.1:findbugs (findbugs) on project system-rules: Unable to
    parse configuration of mojo
    org.codehaus.mojo:findbugs-maven-plugin:3.0.1:findbugs for parameter
    pluginArtifacts: Cannot assign configuration entry 'pluginArtifacts'
    with value '${plugin.artifacts}' of type
    java.util.Collections.UnmodifiableRandomAccessList to property of
    type java.util.ArrayList -> [Help 1]

This is resolved in FindBugs version 3.0.4 and newer.

Author: stefanbirkner

pom.xml

@@ -160,7 +160,7 @@
 				<plugin>
 					<groupId>org.codehaus.mojo</groupId>
 					<artifactId>findbugs-maven-plugin</artifactId>
-					<version>3.0.1</version>
+					<version>3.0.5</version>
 				</plugin>
 				<plugin>
 					<groupId>org.sonatype.plugins</groupId>