software/ors-amarisoft: ue.jinja2.cfg: Fix thinko regarding LTE bandwidth

As Amarisoft documentation says in UEsim LTE bandwidth is defined in MHz, nor in RB:

    https://tech-academy.amarisoft.com/lteue.doc#prop.bandwidth

I checked the history and it was like this since 2015-10-28 release.

-> Fix emitted bandwidth for LTE cell.

Diff for rendered ue-lte.cfg:

```
$ git diff --no-index config/{old,out}
```

```diff
--- a/config/old/ue-lte.cfg
+++ b/config/out/ue-lte.cfg
@@ -1,5 +1,4 @@

-#define N_RB_DL             50

 {
   log_options: "all.level=error,all.max_size=0,nas.level=debug,nas.max_size=1,rrc.level=debug,rrc.max_size=1,phy.level=info,file.rotate=1G,file.path=/dev/null",
@@ -20,7 +19,7 @@ rf_driver: {
     multi_ue: true,
     cells: [
       {
-        bandwidth: N_RB_DL,
+        bandwidth: 10,
         dl_earfcn: 0,
         n_antenna_dl: 2,
         n_antenna_ul: 2,
```

By coincidence this removes last usage of C Preprocessor from ue.jinja2.cfg
and, similarly to enb.jinja2.cfg, makes it to be Jinja2-only.

/cc @lu.xu, @tomo, @xavier_thompson, @Daetalus
/reviewed-by @jhuge
/reviewed-on nexedi/slapos!1521