Fix #1598 - Reduce MasterMetricsIT test resources. (#1599)

Closes  #1598
diff --git a/test/src/main/java/org/apache/accumulo/test/functional/MasterMetricsIT.java b/test/src/main/java/org/apache/accumulo/test/functional/MasterMetricsIT.java
index a2902e2..4fae6a2 100644
--- a/test/src/main/java/org/apache/accumulo/test/functional/MasterMetricsIT.java
+++ b/test/src/main/java/org/apache/accumulo/test/functional/MasterMetricsIT.java
@@ -60,7 +60,7 @@
   private static final long TAIL_DELAY = 5_000;
 
   // number of tables / concurrent compactions used during testing.
-  private final int tableCount = 4;
+  private final int tableCount = 1;
 
   private long maxWait;