fix(emails): darkmode on gmail ios

src/notifications/base/header.hbs

-<mj-section css-class='background' padding='17px' align='center'>
+<mj-section background-color='#1B1C22' padding='17px' align='center'>
   <mj-social
     css-class='button-with-icon'
     icon-size='36px'

src/notifications/monthlyReport.hbs

@@ -21,22 +21,22 @@
     {{#> base/header}}
     {{/base/header}}
 
-    <mj-section  background-color="#121212">
+    <mj-section background-color="#121212">
       <mj-column width="55%" vertical-align="middle">
-        <mj-text color="white" font-weight="900"  font-size="24px">
+        <mj-text color="white" font-weight="900" font-size="24px">
           Bonjour {{username}},
         </mj-text>
         {{#if consumptionTextExist }}
-        <mj-text color="white" font-weight="400"  font-size="18px">Par rapport au mois {{previousMonth}}, vous avez consommé :{{{consumptionText}}}<br /></mj-text>
+        <mj-text color="white" font-weight="400" font-size="18px">Par rapport au mois {{previousMonth}}, vous avez consommé :{{{consumptionText}}}<br /></mj-text>
         {{/if}}
       </mj-column>
       <mj-column width="45%" vertical-align="middle">
-        <mj-image src={{consoImageUrl}} width="132px" align="center" alt="consomation"></mj-image>
+        <mj-image src={{consoImageUrl}} width="132px" align="center" alt="consommation"></mj-image>
       </mj-column>
     </mj-section>
     <mj-section background-color="#121212">
       <mj-column>
-        <mj-text color="white" font-weight="400"  font-size="18px">Retrouvez le détail de vos consommations et plus d'informations dans votre bilan Ecolyo.<br /><br /></mj-text>
+        <mj-text color="white" font-weight="400" font-size="18px">Retrouvez le détail de vos consommations et plus d'informations dans votre bilan Ecolyo.<br /><br /></mj-text>
         <mj-social css-class="button-with-icon" icon-size="36px" mode="horizontal" font-size="20px" font-weight="700">
           <mj-social-element src="{{baseUrl}}/assets/ecolyo-icon.png" name="ecolyo" padding="0 10px 0 0" href="{{clientUrl}}">
             Voir mon bilan
@@ -45,7 +45,7 @@
       </mj-column>
     </mj-section>
     {{#if isContent}}
-      <mj-section background-color="radial-gradient(96.2% 96.2% at 50% 3.8%, #343641 0%, #1B1C22 100%)">
+      <mj-section background-color="#1B1C22">
         <mj-column>
           {{#if isInfo}}
             <mj-text css-class="title" color="white" font-weight="900" font-size="24px" align="center" >

src/notifications/style.hbs

 <mj-style>
   .main div{ line-height: 23.4px !important; font-family: 'Lato', sans-serif
-  !important; } .main .background{ background: radial-gradient(96.2% 96.2% at
-  50% 3.8%, #343641 0%, #1B1C22 100%) !important; }
+  !important; }
 </mj-style>
 <mj-style>
   .small div{ font-weight: 400 !important; font-size: 13px !important;