Fix the 404 nav bar to use the site configurable logo (#104)

Signed-off-by: Emruz Hossain <emruz@appscode.com>

layouts/partials/navigators/navbar-2.html

@@ -1,10 +1,10 @@
 {{ $mainLogo:="assets/images/main-logo.png" }}
 {{ $invertedLogo:="assets/images/inverted-logo.png" }}
-{{ if .Site.Params.logo.main }}
-  {{ $mainLogo = .Site.Params.logo.main }}
+{{ if site.Params.logo.main }}
+  {{ $mainLogo = site.Params.logo.main }}
 {{ end }}
-{{ if .Site.Params.logo.inverted }}
-  {{ $invertedLogo = .Site.Params.logo.inverted }}
+{{ if site.Params.logo.inverted }}
+  {{ $invertedLogo = site.Params.logo.inverted }}
 {{ end }}
 
 <nav class="navbar navbar-expand-xl top-navbar final-navbar shadow">