fix issue https://github.com/tracim/tracim/issues/684, add 5 pixels

frontend/src/css/Login.styl

   &__footer
     position fixed
     top 95%
-    left calc(50% - 152px) // 152px => width of the text / 2
+    left calc(50% - 155px) // 155px => width of the text / 2
     &__text
-      width 305px
+      width 310px
       font-size 17px
 
 @media (min-width: min-lg) and (max-width: max-lg)