erp5_font: don't use lighter on font-face declaration (use 100)

bt5/erp5_font/SkinTemplateItem/portal_skins/erp5_font/lato/lato.css.css

@@ -23,7 +23,7 @@ with Reserved Font Name Lato.
        url('lato-light.woff2') format('woff2'),
        url('lato-light.woff') format('woff'),
        url('lato-light.ttf') format('truetype');
-  font-weight: lighter;
+  font-weight: 100;
   font-style: normal;
 }
 @font-face {

bt5/erp5_font/SkinTemplateItem/portal_skins/erp5_font/open-sans/open-sans.css.css

@@ -22,7 +22,7 @@ Copyright 2012 Google Inc. All Rights Reserved.
        url('open-sans-light.woff') format('woff'),
        url('open-sans-light.woff2') format('woff2')
        url('open-sans-light.ttf') format('truetype');
-  font-weight: lighter;
+  font-weight: 100;
   font-style: normal;
 }
 @font-face {
@@ -44,4 +44,4 @@ Copyright 2012 Google Inc. All Rights Reserved.
        url('open-sans-bold.ttf') format('truetype');
   font-weight: bold;
   font-style: normal;
-}
+}
\ No newline at end of file

bt5/erp5_font/SkinTemplateItem/portal_skins/erp5_font/roboto/roboto-condensed.css.css

@@ -16,7 +16,7 @@
        url('roboto-condensed-light.woff2?portal_skin=CI_new') format('woff2'),
        url('roboto-condensed-light.woff?portal_skin=CI_new') format('woff'),
        url('roboto-condensed-light.ttf?portal_skin=CI_new') format('truetype');
-  font-weight: lighter;
+  font-weight: 100;
   font-style: normal;
 }
 @font-face {

bt5/erp5_font/SkinTemplateItem/portal_skins/erp5_font/roboto/roboto.css.css

@@ -22,7 +22,7 @@ Copyright 2012 Google Inc. All Rights Reserved.
        url('roboto-light.woff2') format('woff2'),
        url('roboto-light.woff') format('woff'),
        url('roboto-light.ttf') format('truetype');
-  font-weight: lighter;
+  font-weight: 100;
   font-style: normal;
 }
 @font-face {

bt5/erp5_font/SkinTemplateItem/portal_skins/erp5_font/source-sans-pro/source-sans-pro.css.css

@@ -24,7 +24,7 @@ Adobe Systems Incorporated in the United States and/or other countries.
        url('source-sans-pro-light.woff2') format('woff2'),
        url('source-sans-pro-light.woff') format('woff'),
        url('source-sans-pro-light.ttf') format('truetype');
-  font-weight: lighter;
+  font-weight: 100;
   font-style: normal;
 }
 @font-face {