grafana: logarithmic scale for service/host counts

Those can get pretty large: in our case we're at 4k service checks,
and we have 20 of those warning right now, which makes them completely
invisible in the graph. By making the axis logarithmic, we're able to
see progression on those lines as well.

grafana/dashboard.json

@@ -1720,7 +1720,8 @@
             "lineWidth": 4,
             "pointSize": 5,
             "scaleDistribution": {
-              "type": "linear"
+              "log": 2,
+              "type": "log"
             },
             "showPoints": "auto",
             "spanNulls": false,
@@ -1845,7 +1846,8 @@
             "lineWidth": 4,
             "pointSize": 5,
             "scaleDistribution": {
-              "type": "linear"
+              "log": 2,
+              "type": "log"
             },
             "showPoints": "auto",
             "spanNulls": false,