[JENKINS-50064] - Suppress FindBugs warning in CLI, switch to the medium level

cli/pom.xml

@@ -13,6 +13,11 @@
   <name>Jenkins cli</name>
   <description>Command line interface for Jenkins</description>
 
+  <properties>
+    <!-- TODO: remove once Medium level is set in the core (JENKINS-36716) -->
+    <findbugs.threshold>Medium</findbugs.threshold>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.powermock</groupId>
@@ -67,6 +72,11 @@
       <artifactId>trilead-ssh2</artifactId>
       <version>build214-jenkins-1</version>
     </dependency>
+    <dependency>
+      <groupId>com.google.code.findbugs</groupId>
+      <artifactId>annotations</artifactId>
+      <scope>provided</scope>
+    </dependency>
   </dependencies>
 
   <build>

cli/src/main/java/hudson/cli/SSHCLI.java

@@ -51,6 +51,8 @@ import org.apache.sshd.common.util.io.NoCloseInputStream;
 import org.apache.sshd.common.util.io.NoCloseOutputStream;
 import org.apache.sshd.common.util.security.SecurityUtils;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
 /**
  * Implements SSH connection mode of {@link CLI}.
  * In a separate class to avoid any class loading of {@code sshd-core} when not using {@code -ssh} mode.
@@ -59,6 +61,7 @@ import org.apache.sshd.common.util.security.SecurityUtils;
  */
 class SSHCLI {
 
+    @SuppressFBWarnings(value = "RCN_REDUNDANT_NULLCHECK_OF_NULL_VALUE", justification = "Due to whatever reason FindBugs reports it fot try-with-resources")
     static int sshConnection(String jenkinsUrl, String user, List<String> args, PrivateKeyProvider provider, final boolean strictHostKey) throws IOException {
         Logger.getLogger(SecurityUtils.class.getName()).setLevel(Level.WARNING); // suppress: BouncyCastle not registered, using the default JCE provider
         URL url = new URL(jenkinsUrl + "login");