Bump gson from 2.8.6 to 2.8.9

Bumps [gson](https://github.com/google/gson) from 2.8.6 to 2.8.9.
- [Release notes](https://github.com/google/gson/releases)
- [Changelog](https://github.com/google/gson/blob/master/CHANGELOG.md)
- [Commits](https://github.com/google/gson/compare/gson-parent-2.8.6...gson-parent-2.8.9)

---
updated-dependencies:
- dependency-name: com.google.code.gson:gson
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pom.xml b/pom.xml
index fec112e..5e07146 100644
--- a/pom.xml
+++ b/pom.xml
@@ -27,7 +27,7 @@
         <apache.httpcomponents.ver>4.5.13</apache.httpcomponents.ver>
         <apache.common.lang.ver>3.11</apache.common.lang.ver>
         <commons.validator.ver>1.7</commons.validator.ver>
-        <gson.ver>2.8.6</gson.ver>
+        <gson.ver>2.8.9</gson.ver>
         <log4j.ver>2.14.0</log4j.ver>
         <nlpcraft.ver>0.9.0</nlpcraft.ver>
         <junit.ver>5.7.0</junit.ver>