MDEV-7277 Server crashes on creating/opening tables on Windows debug build.

        The srid variable was used uninitialised when the field wasn't GIS.
        Only problem is that it makes the debugger unhappy. Still added
        the initialization.

sql/table.cc

@@ -1445,7 +1445,7 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
     LEX_STRING comment;
     Virtual_column_info *vcol_info= 0;
     bool fld_stored_in_db= TRUE;
-    uint gis_length, gis_decimals, srid;
+    uint gis_length, gis_decimals, srid= 0;
 
     if (new_frm_ver >= 3)
     {