deps: update dependency org.apache.httpcomponents:httpcore to v4.4.15 (#1171)

Author: renovate-bot

pom.xml

@@ -139,7 +139,7 @@
  <dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpcore</artifactId>
- <version>4.4.14</version>
+ <version>4.4.15</version>
  <scope>test</scope>
  </dependency>