Fix tabindex on login/registration page inputs

In the login/registration page, pressing the 'tab' button now selects
the next input field.

GitLab: #157
Change-Id: Ic2475442036490fa6d867673b11f0818d7158c0d
diff --git a/client/src/components/Input.tsx b/client/src/components/Input.tsx
index ec840c4..c35bbab 100644
--- a/client/src/components/Input.tsx
+++ b/client/src/components/Input.tsx
@@ -113,7 +113,12 @@
         InputProps={{
           startAdornment,
           endAdornment: (
-            <InfoButton tooltipTitle={tooltipTitle} {...infoButtonProps} onClick={dialogHandler.openDialog} />
+            <InfoButton
+              tabIndex={-1}
+              tooltipTitle={tooltipTitle}
+              {...infoButtonProps}
+              onClick={dialogHandler.openDialog}
+            />
           ),
           ...props.InputProps,
         }}