CI: modified also RRU config

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

ci-scripts/conf_files/rru.fdd.band7.conf

@@ -20,7 +20,7 @@ RUs = (
 THREAD_STRUCT = (
   {
     #three config for level of parallelism "PARALLEL_SINGLE_THREAD", "PARALLEL_RU_L1_SPLIT", or "PARALLEL_RU_L1_TRX_SPLIT"
-    parallel_config    = "PARALLEL_RU_L1_TRX_SPLIT";
+    parallel_config    = "PARALLEL_SINGLE_THREAD";
     #two option for worker "WORKER_DISABLE" or "WORKER_ENABLE"
     worker_config      = "WORKER_ENABLE";
   }