Fix precache warnings for some client-side shells. Not exactly necessary

but pleases the compiler.

src/shared/w_glock.qc

@@ -89,6 +89,7 @@ w_glock_precache(void)
 #else
 	precache_model("models/v_9mmhandgun.mdl");
 	precache_model("models/p_9mmhandgun.mdl");
+	precache_model("models/shell.mdl");
 	Sound_Precache("modelevent_shell.land");
 #endif
 }

src/shared/w_shotgun.qc

@@ -90,6 +90,7 @@ void w_shotgun_precache(void)
 #else
 	precache_model("models/v_shotgun.mdl");
 	precache_model("models/p_shotgun.mdl");
+	precache_model("models/shotgunshell.mdl");
 	Sound_Precache("modelevent_shotgunshell.land");
 #endif
 }