Bump com.google.protobuf:protobuf-gradle-plugin from 0.9.4 to 0.9.5 (#314)

Bumps [com.google.protobuf:protobuf-gradle-plugin](https://github.com/google/protobuf-gradle-plugin) from 0.9.4 to 0.9.5.
- [Release notes](https://github.com/google/protobuf-gradle-plugin/releases)
- [Commits](google/protobuf-gradle-plugin@v0.9.4...v0.9.5)

---
updated-dependencies:
- dependency-name: com.google.protobuf:protobuf-gradle-plugin
  dependency-version: 0.9.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Max Lambrecht <maxlambrecht@gmail.com>

Author: dependabot[bot]

java-spiffe-core/build.gradle

@@ -4,7 +4,7 @@ buildscript {
     }
 
     dependencies {
-        classpath group: 'com.google.protobuf', name: 'protobuf-gradle-plugin', version: '0.9.4'
+        classpath group: 'com.google.protobuf', name: 'protobuf-gradle-plugin', version: '0.9.5'
     }
 }