GerritPrometheusExporter: Remove superfluous semicolon

Change-Id: Ib89aebe654a67a49b9caa260d5dd63ac44477310

src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
index 8cd6c56..674bf32 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/metricsreporters/GerritPrometheusExporter.java
@@ -49,4 +49,4 @@
       httpResponse.sendError(HttpServletResponse.SC_FORBIDDEN, "Forbidden access");
     }
   }
-};
+}