Disallow empty regex in PQ+

Change-Id: Ifcda331007866616e6bd079e8d331dec9d1f880a
Reviewed-on: https://korap.ids-mannheim.de/gerrit/c/KorAP/Koral/+/7512
Reviewed-by: Nils Diewald <nils@diewald-online.de>
diff --git a/pom.xml b/pom.xml
index 8e38774..6bdd557 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
 	<groupId>de.ids_mannheim.korap</groupId>
 	<artifactId>Koral</artifactId>
-	<version>0.40.0</version>
+	<version>0.41.0</version>
 	<packaging>jar</packaging>
 	<name>Koral</name>
 	<url>https://korap.ids-mannheim.de</url>