MDL-42451 installation: Allow enter key to proceed

Author: Chocolate-lightning

lib/installlib.php

@@ -385,9 +385,9 @@ function install_print_footer($config, $reload=false) {
     global $CFG;
 
     if ($config->stage > INSTALL_WELCOME) {
-        $first = '<input type="submit" id="previousbutton" name="previous" value="&laquo; '.s(get_string('previous')).'" />';
+        $first = '<input type="submit" id="previousbutton" class="btn btn-secondary ml-auto" name="previous" value="&laquo; '.s(get_string('previous')).'" />';
     } else {
-        $first = '<input type="submit" id="previousbutton" name="next" value="'.s(get_string('reload')).'" />';
+        $first = '<input type="submit" id="previousbutton" class="btn btn-secondary ml-auto" name="next" value="'.s(get_string('reload')).'" />';
         $first .= '<script type="text/javascript">
 //<![CDATA[
     var first = document.getElementById("previousbutton");
@@ -398,12 +398,12 @@ function install_print_footer($config, $reload=false) {
     }
 
     if ($reload) {
-        $next = '<input type="submit" id="nextbutton" class="btn btn-primary" name="next" value="'.s(get_string('reload')).'" />';
+        $next = '<input type="submit" id="nextbutton" class="btn btn-primary ml-1 mr-auto" name="next" value="'.s(get_string('reload')).'" />';
     } else {
-        $next = '<input type="submit" id="nextbutton" class="btn btn-primary" name="next" value="'.s(get_string('next')).' &raquo;" />';
+        $next = '<input type="submit" id="nextbutton" class="btn btn-primary ml-1 mr-auto" name="next" value="'.s(get_string('next')).' &raquo;" />';
     }
 
-    echo '</fieldset><fieldset id="nav_buttons">'.$first.$next.'</fieldset>';
+    echo '</fieldset><div id="nav_buttons" class="mb-3 btn-group w-100 flex-row-reverse">'.$next.$first.'</div>';
 
     $homelink  = '<div class="sitelink">'.
        '<a title="Moodle '. $CFG->target_release .'" href="http://docs.moodle.org/en/Administrator_documentation" onclick="this.target=\'_blank\'">'.