Remove icon images on mailers

app/views/mailer/budget_investment_created.html.erb

@@ -26,7 +26,6 @@
       <tr>
         <td style="padding-bottom: 12px; text-align: center;">
           <%= link_to budget_investment_url(@investment.budget, @investment, anchor: "social-share"), style: css_for_mailer_button do %>
-            <%= image_tag("icon_mailer_share.png", style: "border: 0; display: inline-block; width: 100%; max-width: 16px", alt: "") %>
             <%= t("mailers.budget_investment_created.share") %>
           <% end %>
         </td>

app/views/mailer/budget_investment_selected.html.erb

@@ -13,7 +13,6 @@
       <tr>
         <td style="padding-bottom: 12px; text-align: center;">
           <%= link_to budget_investment_url(@investment.budget, @investment, anchor: "social-share"), style: css_for_mailer_button do %>
-            <%= image_tag("icon_mailer_share.png", style: "border: 0; display: inline-block; width: 100%; max-width: 16px", alt: "") %>
             <%= t("mailers.budget_investment_selected.share_button") %>
           <% end %>
         </td>

app/views/mailer/direct_message_for_receiver.html.erb

@@ -12,7 +12,6 @@
       <tr>
         <td style="padding-bottom: 12px; padding-top: 24px; text-align: center;">
           <%= link_to user_url(@direct_message.sender), style: css_for_mailer_button, target: "_blank" do %>
-            <%= image_tag("icon_mailer_reply.png", style: "border: 0; display: inline-block; width: 100%; max-width: 12px; vertical-align: sub;", alt: "") %>
             <%= t("mailers.direct_message_for_receiver.reply",
                 sender: @direct_message.sender.name) %>
           <% end %>

app/views/mailer/proposal_notification_digest.html.erb

@@ -32,12 +32,10 @@
                 <tr>
                   <td style="padding-bottom: 12px;">
                     <%= link_to proposal_url(notification.notifiable.proposal, anchor: "social-share"), style: css_for_mailer_button do %>
-                      <%= image_tag("icon_mailer_share.png", style: "border: 0; display: inline-block; width: 100%; max-width: 16px", alt: "") %>
                       <%= t("mailers.proposal_notification_digest.share") %>
                     <% end %>
 
                     <%= link_to proposal_url(notification.notifiable.proposal, anchor: "comments"), style: css_for_mailer_button do %>
-                      <%= image_tag("icon_mailer_comment.png", style: "border: 0; display: inline-block; width: 100%; max-width: 16px; vertical-align: middle;", alt: "") %>
                       <%= t("mailers.proposal_notification_digest.comment") %>
                     <% end %>
                   </td>