AStyle: fix indentation for longer lines

Long lines like this would have parameters misaligned but shorter lines would be OK.

```
 void LoRaMac::check_frame_size(uint16_t size)
 {
     uint8_t value = _lora_phy.get_max_payload(_mcps_indication.rx_datarate,
-                                              _params.is_repeater_supported);
+                    _params.is_repeater_supported);
+
+    _lora_phy.a(_mcps_indication.b,
+                b.is_repeater_supported);
```

With this option (applied to the code above), we get

```
@@ -319,6 +319,9 @@ void LoRaMac::check_frame_size(uint16_t size)
     uint8_t value = _lora_phy.get_max_payload(_mcps_indication.rx_datarate,
                                               _params.is_repeater_supported);

+    _lora_phy.a(_mcps_indication.b,
+                b.is_repeater_supported);
```

Both are aligned the same. However there is a limit of astyle - 120 columns for this.
We do in most cases lines from 80 to 120 as suggested in our code lines thus this should
be good.

.astylerc

@@ -31,3 +31,7 @@ align-reference=name
 # Attach { for classes and namespaces
 attach-namespaces
 attach-classes
+
+# Extend longer lines, define maximum 120 value. This results in aligned code,
+# otherwise the lines are broken and not consistent 
+max-continuation-indent=120