Fix compile deprecation warning

warning: [removal] AccessControlException in java.security has been deprecated and marked for removal

source/net/yacy/cora/protocol/ftp/FTPClient.java

@@ -2520,9 +2520,7 @@ public class FTPClient {
             c.cmd = new String[]{"exit"};
             c.EXIT();
             return v;
-        } catch (final java.security.AccessControlException e) {
+        } catch (final SecurityException | IOException e) {
-            return null;
-        } catch (final IOException e) {
             return null;
         }
     }
@@ -2536,7 +2534,7 @@ public class FTPClient {
             c.exec("ls", true);
             c.exec("close", false);
             c.exec("exit", false);
-        } catch (final java.security.AccessControlException e) {
+        } catch (final SecurityException e) {
         }
     }
 
@@ -2782,7 +2780,7 @@ public class FTPClient {
             c.exec("get " + remoteFile + " " + localPath.getAbsoluteFile().toString(), false);
             c.exec("close", false);
             c.exec("exit", false);
-        } catch (final java.security.AccessControlException e) {
+        } catch (final SecurityException e) {
         }
     }