Update log4j to deal with CVE-2021-44228

Change-Id: Ie8772b0275433e0c2a302a87c43bae4db0ec8219
diff --git a/pom.xml b/pom.xml
index b6e74d5..6d03fb7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -40,7 +40,7 @@
 		<antlr4.version>4.9.2</antlr4.version>
 		<antlr3.version>3.5.2</antlr3.version>
 		<java.version>1.8</java.version>
-		<log4j.version>2.14.1</log4j.version>
+		<log4j.version>[2.15.0,)</log4j.version>
 	</properties>
 	
 	<repositories>