Exclude log4j:log4j in favor of org.slf4j:log4j-over-slf4j

Closes gh-1660

Author: wilkinsona

spring-boot-starters/spring-boot-starter-data-solr/pom.xml

@@ -25,6 +25,12 @@
 		<dependency>
 			<groupId>org.apache.solr</groupId>
 			<artifactId>solr-solrj</artifactId>
+			<exclusions>
+				<exclusion>
+					<groupId>log4j</groupId>
+					<artifactId>log4j</artifactId>
+				</exclusion>
+			</exclusions>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework</groupId>