Updated French translation of MSG_MMU_LOAD_FAILED c=20 as @awenelo suggested

Firmware/Configuration.h

@@ -17,7 +17,7 @@ extern PGM_P sPrinterName;
 
 // Firmware version
 #define FW_VERSION "3.10.0-RC2"
-#define FW_COMMIT_NR 4104
+#define FW_COMMIT_NR 4903
 // FW_VERSION_UNKNOWN means this is an unofficial build.
 // The firmware should only be checked into github with this symbol.
 #define FW_DEV_VERSION FW_VERSION_UNKNOWN

lang/lang_en_fr.txt

@@ -608,7 +608,7 @@
 
 #MSG_MMU_LOAD_FAILED c=20
 "MMU load failed     "
-"Echec chargement MMU"
+"Def. charg. MMU"
 
 #MSG_MMU_LOAD_FAILS c=15
 "MMU load fails"