Fixed the crash that would occur if "Use BIOS file" was selected without a BIOS file specified.

src/gba/GBA.cpp

@@ -3370,7 +3370,7 @@ void CPUInit(const char *biosFileName, bool useBiosFile)
   eepromInUse = 0;
   useBios = false;
 
-  if(useBiosFile) {
+  if(useBiosFile && strlen(biosFileName) > 0) {
     int size = 0x4000;
     if(utilLoad(biosFileName,
                 CPUIsGBABios,

src/wx/cmdevents.cpp

@@ -2505,7 +2505,10 @@ EVT_HANDLER(wxID_ABOUT, "About...")
 	ai.SetName(wxT("VisualBoyAdvance-M"));
 	wxString version = wxT("");
 #ifndef FINAL_BUILD
-	version = version + wxT("-") + wxT(SVN_REV_STR);
+	if (!version.IsEmpty())
+		version = version + wxT("-");
+
+	version = version + wxT(SVN_REV_STR);
 #endif
 	ai.SetVersion(version);
 	// setting website, icon, license uses custom aboutbox on win32 & macosx