fix spelling as pointed out by @jodytate that got nuked in the merge

sticky-footer-navbar.html

@@ -20,7 +20,7 @@ title: Sticky footer with navbar template
     min-height: 100%;
     height: auto !important;
     height: 100%;
-    /* Negative indent footer by it's height */
+    /* Negative indent footer by its height */
     margin: 0 auto -60px;
   }
 

sticky-footer.html

@@ -20,7 +20,7 @@ title: Sticky footer template
     min-height: 100%;
     height: auto !important;
     height: 100%;
-    /* Negative indent footer by it's height */
+    /* Negative indent footer by its height */
     margin: 0 auto -60px;
   }