[FIX] account_ebics: IndexError in _split_camt for camt.054

Fix IndexError in _split_camt when camt.054 has no currency at statement level.
This commit implements the following changes:
- discard statements without entries before attempting currency extraction
- fall back to Ntry/Amt/@Ccy for camt.054 when Acct/Ccy and Bal/Amt/@Ccy are absent

account_ebics/__manifest__.py

@@ -3,7 +3,7 @@
 
 {
     "name": "EBICS banking protocol",
-    "version": "18.0.1.2.1",
+    "version": "18.0.1.2.2",
     "license": "LGPL-3",
     "author": "Noviat",
     "website": "https://www.noviat.com/",