Resolve "RugoFond: ajout du strickler equivalent dans les résultats complémentaires"

Closes #673 (closed)

src/locale/messages.en.json

@@ -380,6 +380,7 @@
     "INFO_LIB_TOTAL": "Total",
     "INFO_LIB_V_GUIDETECH": "Technical guide velocity",
     "INFO_LIB_V": "Average velocity",
+    "INFO_LIB_KS": "Equivalent strickler",
     "INFO_LIB_VDEB": "Conveyance velocity",
     "INFO_LIB_VMAX": "Maximal velocity",
     "INFO_LIB_VG": "Averaged velocity between blocks",