Added castor::exception::InvalidConfiguration in order to work towards

addressing the following RFE:

bug #67945: RFE: The mighunter should not start if the migration and stream policy modules are not configured properly

mediachanger/castorrmc/common/serror.c

@@ -63,6 +63,7 @@ char    *sys_serrlist[SEMAXERR-SEBASEOFF+2]=
    "Too many symbolic links",
    "No port in range",
    "No value",
+   "Invalid configuration",
    "BAD ERROR NUMBER"
   };
 

mediachanger/castorrmc/h/serrno.h

@@ -76,8 +76,9 @@
 #define SELOOP          SEBASEOFF+40    /* Too many symbolic links      */
 #define SENOPORTINRANGE SEBASEOFF+41    /* No port in range             */
 #define SENOVALUE       SEBASEOFF+42    /* No value                     */
+#define SEINVALIDCONFIG SEBASEOFF+43    /* Invalid configuration        */
 
-#define SEMAXERR        SEBASEOFF+42    /* Maximum error number         */
+#define SEMAXERR        SEBASEOFF+43    /* Maximum error number         */
 
 #define SERRNO  (serrno - SEBASEOFF)    /* User convenience             */
 /*