Merge some repeated codes to the partial

app/views/projects/issues/_issue_by_email.html.haml

+.issues-footer.text-center
+  %button.issue-email-modal-btn{ type: "button", data: { toggle: "modal", target: "#issue-email-modal" } }
+    Email a new issue to this project
+
 #issue-email-modal.modal.fade{ tabindex: "-1", role: "dialog" }
   .modal-dialog{ role: "document" }
     .modal-content

app/views/projects/issues/index.html.haml

@@ -24,12 +24,9 @@
     = render 'shared/issuable/filter', type: :issues
 
     .issues-holder
-      = render "issues"
+      = render 'issues'
       - if new_issue_email
-        .issues-footer.text-center
-          %button.issue-email-modal-btn{ type: "button", data: { toggle: "modal", target: "#issue-email-modal" } }
-            Email a new issue to this project
-        = render "issue_by_email", email: new_issue_email
+        = render 'issue_by_email', email: new_issue_email
   - else
     .blank-state.blank-state-welcome
       %h2.blank-state-title.blank-state-welcome-title
@@ -47,7 +44,4 @@
         = link_to new_namespace_project_issue_path(@project.namespace, @project), class: "btn btn-new", title: "New Issue", id: "new_issue_link" do
           New Issue
         - if new_issue_email
-          .issues-footer.text-center
-            %button.issue-email-modal-btn{ type: "button", data: { toggle: "modal", target: "#issue-email-modal" } }
-              Email a new issue to this project
-          = render "issue_by_email", email: new_issue_email
+          = render 'issue_by_email', email: new_issue_email