Remove ability to load plugins with spaces in their name.

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

paper-api/src/main/java/org/bukkit/plugin/SimplePluginManager.java

@@ -136,11 +136,8 @@ public final class SimplePluginManager implements PluginManager {
                     server.getLogger().log(Level.SEVERE, "Could not load '" + file.getPath() + "' in folder '" + directory.getPath() + "': Restricted Name");
                     continue;
                 } else if (description.rawName.indexOf(' ') != -1) {
-                    server.getLogger().warning(String.format(
-                        "Plugin `%s' uses the space-character (0x20) in its name `%s' - this will not work in Minecraft 1.12",
-                        description.getFullName(),
-                        description.rawName
-                        ));
+                    server.getLogger().log(Level.SEVERE, "Could not load '" + file.getPath() + "' in folder '" + directory.getPath() + "': uses the space-character (0x20) in its name");
+                    continue;
                 }
             } catch (InvalidDescriptionException ex) {
                 server.getLogger().log(Level.SEVERE, "Could not load '" + file.getPath() + "' in folder '" + directory.getPath() + "'", ex);