revert changes to DoOpenDll, OpenDll, LoadDll funcs

Author: Alexey-T

demos_lazarus/Demo01/project1.res

@@ -3341,14 +3341,19 @@ procedure TPythonInputOutput.UpdateCurrentThreadLine;
 (*******************************************************)
 
 procedure TDynamicDll.DoOpenDll(const aDllName : String);
+var
+  S: String;
 begin
   if not IsHandleValid then
   begin
+    FDllName := aDllName;
+    S := GetDllPath+DllName;
+
     {$ifdef windows}
-    FDLLHandle := Windows.LoadLibrary(PChar(aDllName));
+    FDLLHandle := Windows.LoadLibrary(PChar(S));
     {$else}
     //Linux: need here RTLD_GLOBAL, so Python can do "import ctypes"
-    FDLLHandle := PtrInt(dlopen(PAnsiChar(aDllName), RTLD_LAZY+RTLD_GLOBAL));
+    FDLLHandle := PtrInt(dlopen(PAnsiChar(S), RTLD_LAZY+RTLD_GLOBAL));
     {$endif}
   end;
 end;
@@ -3389,7 +3394,7 @@ procedure  TDynamicDll.OpenDll(const aDllName : String);
 
   if not IsHandleValid then begin
 {$IFDEF windows}
-    s := Format('Error %d: Could not open Dll "%s"',[GetLastError, aDllName]);
+    s := Format('Error %d: Could not open Dll "%s"',[GetLastError, DllName]);
 {$else}
     s := Format('Error: Could not open Dll "%s"',[DllName]);
 {$ENDIF}
@@ -3454,7 +3459,7 @@ function  TDynamicDll.IsHandleValid : Boolean;
 
 procedure TDynamicDll.LoadDll;
 begin
-  OpenDll(DllPath + DllName);
+  OpenDll( DllName );
 end;
 
 procedure TDynamicDll.UnloadDll;