Fix truncated button icons on Safari

Removing margin offset to fix issue with button icons being
visually truncated on Safari. Removing additional redundant
code around same icon/buttons.

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: Ie1ef89023a043a70a0126a21be57febb9afae19a
diff --git a/app/configuration/styles/snmp.scss b/app/configuration/styles/snmp.scss
index a249118..6e99c80 100644
--- a/app/configuration/styles/snmp.scss
+++ b/app/configuration/styles/snmp.scss
@@ -9,6 +9,6 @@
     padding-right: 1.5rem;
   }
   .btn-add-manager {
-    padding: 0;
+    padding-left: 0;
   }
 }