gui: fix incorrect settings loading

jadx-gui/src/main/java/jadx/gui/settings/JadxSettings.java

@@ -43,6 +43,12 @@ public class JadxSettings extends JadxCLIArgs {
 		JadxSettingsAdapter.store(this);
 	}
 
+	public void fixOnLoad() {
+		if (threadsCount <= 0) {
+			threadsCount = DEFAULT_THREADS_COUNT;
+		}
+	}
+
 	public String getLastOpenFilePath() {
 		return lastOpenFilePath;
 	}

jadx-gui/src/main/java/jadx/gui/settings/JadxSettingsAdapter.java

@@ -50,6 +50,7 @@ public class JadxSettingsAdapter {
 				return new JadxSettings();
 			}
 			LOG.debug("Loaded settings: {}", makeString(settings));
+			settings.fixOnLoad();
 			return settings;
 		} catch (Exception e) {
 			LOG.error("Error load settings", e);