minor spacing stuff

src/component/ComponentHistory.tsx

@@ -33,7 +33,7 @@ export default function ComponentHistory(props: Props) {
             offset: or(res.data.nextOffset, 0)
           });
         })
-        .catch((err: any) => {
+        .catch((_err: any) => {
           resolve({
             records: [] as Record[],
             total: 0,

src/device/DevicesSummary.tsx

@@ -88,9 +88,6 @@ export default function DevicesSummary(props: Props) {
   return (
     <Grid2 container spacing={1} marginBlock={1} >
       <Grid2 size={{xs: 6, sm: 3}}>
-        {loadingStats ? 
-          <Skeleton className={classes.card} />
-        :
         <Card 
           className={
             classNames(
@@ -119,7 +116,6 @@ export default function DevicesSummary(props: Props) {
             </Grid2>
           </Grid2>
         </Card>
-        }
       </Grid2>
       <Grid2 size={{xs: 6, sm: 3}}>
         <Card 

src/pages/DeviceHistory.tsx

@@ -1,7 +1,6 @@
 import { 
   Box, 
   Theme, 
-  Toolbar 
 } from "@mui/material";
 import SmartBreadcrumb from "common/SmartBreadcrumb";
 import { useDeviceAPI, useSnackbar } from "hooks";

src/pages/Devices.tsx

@@ -1,5 +1,5 @@
 import { DeveloperBoard as ProvisionIcon, LibraryAdd as CreateGroupIcon } from "@mui/icons-material";
-import { Box, Chip, CircularProgress, IconButton, Tab, Tabs, Theme, Tooltip, Typography } from "@mui/material";
+import { Box, Chip, CircularProgress, IconButton, Skeleton, Tab, Tabs, Theme, Tooltip, Typography } from "@mui/material";
 import { blue, green } from "@mui/material/colors";
 import { makeStyles } from "@mui/styles";
 import ResponsiveTable, { Column } from "common/ResponsiveTable";
@@ -354,7 +354,7 @@ export default function Devices() {
         >
           <Tab wrapped value={"all"} label="All" />
           {groupsLoading ? 
-            <Tab value={"loading"} label={<CircularProgress />}/>
+            <Tab value={"loading"} label={<Skeleton variant="rectangular" height={24} width={128} animation="pulse" />}/>
           : groups.map((group, index) => {
             if (group.id()) return (
               <Tab className={classes.tab} wrapped value={group.id().toString()} label={<Typography variant="inherit" noWrap>{group.name()}</Typography>} key={"group-tab-"+index}/>