String fix.

include/errors.php

@@ -54,7 +54,7 @@ $aErrors['SQM_IMAP_APPEND_QUOTA_ERROR'] = array(
     'category' => SQM_ERROR_IMAP,
     'message'  => _( "Out of quota error."),
     'link'     => '',
-    'tip'      => _("Remove unneccessary messages from your folder. Start with your Trash folder.")
+    'tip'      => _("Remove unneccessary messages from your folders. Start with your Trash folder.")
 );
 
 $aErrors['SQM_IMAP_APPEND_ERROR'] = array(

src/help.php

@@ -197,7 +197,7 @@ if ( $chapter == 0 || !isset( $helpdir[$chapter-1] ) ) {
     } elseif (file_exists("../help/en_US/" . $helpdir[$chapter-1])) {
         // If the selected language can't be found, try English.
         $doc = file("../help/en_US/" . $helpdir[$chapter-1]);
-        error_box(_("This chapter in not available in the selected language. It will be displayed in English instead."));
+        error_box(_("This chapter is not available in the selected language. It will be displayed in English instead."));
         echo '<br />';
     } else {
         // If English can't be found, the chapter went MIA.