Command block names are not nullable

By: md_5 <git@md-5.net>

paper-server/nms-patches/CommandBlockListenerAbstract.patch

@@ -35,3 +35,15 @@
                      } catch (Throwable throwable) {
                          CrashReport crashreport = CrashReport.a(throwable, "Executing command block");
                          CrashReportSystemDetails crashreportsystemdetails = crashreport.a("Command to be executed");
+@@ -141,6 +139,11 @@
+     }
+ 
+     public void setName(IChatBaseComponent ichatbasecomponent) {
++        // CraftBukkit start
++        if (ichatbasecomponent == null) {
++            ichatbasecomponent = new ChatComponentText("@");
++        }
++        // CraftBukkit end
+         this.h = ichatbasecomponent;
+     }
+