Delete temporary secdb init files immediately (with thanks to Vlad)

Author: reevespaul

builds/install/arch-specific/win32/FirebirdInstall.iss

@@ -910,6 +910,8 @@ begin
     Log( 'In function InitSecurityDB FindInFile found an error in ' + OutputStr );
   end;
 
+  DeleteFile( InputStr );
+  DeleteFile( OutputStr );
 end;