amarisoft_enb.cfg.tmpl: seperate PRACH root sequences for cells

seperate the root sequence index for each cell a bit more to
avoid detection of a single PRACH in both cells

Change-Id: I5aea1a27939c880944779c282e902465ab513715
diff --git a/src/osmo_gsm_tester/templates/amarisoft_enb.cfg.tmpl b/src/osmo_gsm_tester/templates/amarisoft_enb.cfg.tmpl
index 18a37c4..c5b8a1e 100644
--- a/src/osmo_gsm_tester/templates/amarisoft_enb.cfg.tmpl
+++ b/src/osmo_gsm_tester/templates/amarisoft_enb.cfg.tmpl
@@ -74,7 +74,7 @@
     cell_id: ${cell.cell_id},
     n_id_cell: ${cell.pci},
     tac: 0x0007,
-    root_sequence_index: ${loop.index + 204}, /* PRACH root sequence index */
+    root_sequence_index: ${loop.index * 10 + 204}, /* PRACH root sequence index */
 
     ncell_list: [
 %for ncell in enb.cell_list: