workaround for unitialized memory read on import set

+ if we import a set in draw3 (from .xsd file), defcfg won't set _configId in imported params, leaving it uninitialized and leading to strange errors
+ initialize _configId to invalid value, so at worst it will fail in a more comprehensible way
+ we cannot throw from GetConfigId because of the "Caught unhandled unknown exception; terminating" wx behaviour which hides the place in code from which an exception is thrown. Overriding OnUnhandledException and OnExceptionInMainLoop in szapp (and e.g. calling abort, terminate from there) has no effect.
+ introduced a workaround in a completely different part of code than importing set, as the bug in importing set would be hard to find

libSzarp2/include/szarp_config.h

@@ -840,7 +840,7 @@ public:
 
 	void SetParamId(unsigned paramId) { _paramId = paramId; }
 
-	unsigned GetConfigId() const { return _configId; }
+	int GetConfigId();
 
 	void SetConfigId(unsigned configId) { _configId = configId; }
 
@@ -868,7 +868,7 @@ protected:
 
 	unsigned _paramId;
 
-	unsigned _configId;
+	int _configId{-1};	// if left uninitialized, this can lead to ugly errors, so initialize to invalid value
 
 	TRaport	* _raports;	/**< List of raports for param */
 	TDraw * _draws;		/**< List of draws for param */

libSzarp2/ipk/tparam.cc

@@ -750,6 +750,17 @@ std::wstring TParam::GetGlobalName() const {
 	return sc->GetPrefix() + L":" + _name;
 }
 
+int TParam::GetConfigId()
+{
+	if (_configId < 0) {
+		// _configId should be set, but it's not so let's try to workaround it
+		if (GetSzarpConfig()) {
+			SetConfigId(GetSzarpConfig()->GetConfigId());
+		}
+	}
+	return _configId;
+}
+
 namespace szarp {
 
 std::wstring substituteWildcards(const std::wstring &name, const std::wstring &ref)