More rigorous test for existing configures sec db

This should fix #7826

builds/install/arch-specific/win32/FirebirdInstall.iss

@@ -615,6 +615,8 @@ program Setup;
 // a) Form a module or have common functionality
 // b) Debugged.
 // This hopefully keeps the main script simpler to follow.
+const
+ UNDEFINED = -1;
 
 Var
   InstallRootDir: String;
@@ -630,6 +632,7 @@ Var
                                 // databases.conf, fbtrace.conf and the security database.
 
   SYSDBAPassword: String;       // SYSDBA password
+  init_secdb: integer;          // Is set to UNDEFINED by default in InitializeSetup
 
 #ifdef setuplogging
 // Not yet implemented - leave log in %TEMP%
@@ -722,6 +725,7 @@ begin
   InitExistingInstallRecords;
   AnalyzeEnvironment;
   result := AnalysisAssessment;
+  init_secdb := UNDEFINED;
 
 end;
 
@@ -1035,7 +1039,8 @@ begin
       IncrementSharedCount(Is64BitInstallMode, GetAppPath+'\security4.fdb', false);
       IncrementSharedCount(Is64BitInstallMode, GetAppPath+'\replication.conf', false);
 
-			InitSecurityDB;
+      if init_secdb = 1 then
+        InitSecurityDB;
 
       //Fix up conf file
       UpdateFirebirdConf;

builds/install/arch-specific/win32/FirebirdInstallEnvironmentChecks.inc

@@ -1200,13 +1200,20 @@ end;
 
 function ConfigureAuthentication: boolean;
 begin
-	if IsNotServerInstall then
-		Result := false
-	else
-		if FileExists(WizardDirValue + '\security4.fdb') then
-			Result := false
-		else
-			Result := true;
+  // if it is the first time we are called test for existence of the security db
+  if init_secdb = UNDEFINED then begin
+    if FileExists(WizardDirValue + '\security4.fdb') then
+      Result := false
+    else
+      Result := true
+    end
+  else
+    // else the result is the current setting of init_secdb
+    Result := Boolean(init_secdb);
+
+  // Whatever the result, cast it to an integer and update init_secdb
+  init_secdb := Integer(Result);
+
 end;