Merge pull request #5271 from JabRef/dependabot/gradle/com.google.gua…

…va-guava-28.1-jre

Bump guava from 28.0-jre to 28.1-jre

build.gradle

@@ -150,7 +150,7 @@ dependencies {
 
     compile 'org.postgresql:postgresql:42.2.6'
 
-    compile ('com.google.guava:guava:28.0-jre') {
+    compile ('com.google.guava:guava:28.1-jre') {
         // TODO: Remove this as soon as https://github.com/google/guava/issues/2960 is fixed
         exclude module: "jsr305"
     }