port: add spawn with weapon mp option

unfortunately it does not fit in the save buffer and won't save

src/include/constants.h

@@ -2889,6 +2889,7 @@
 #define MPOPTION_HTM_SHOWONRADAR        0x00040000
 #define MPOPTION_PAC_HIGHLIGHTTARGET    0x00080000
 #define MPOPTION_PAC_SHOWONRADAR        0x00100000
+#define MPOPTION_SPAWNWITHWEAPON        0x00200000
 
 #define MPPAUSEMODE_UNPAUSED 0
 #define MPPAUSEMODE_PAUSED   1