refactor: remove <util/system.h> include from wallet.h

Since we no longer store a ref to the global `ArgsManager`
inside the wallet, we can move the util/system.h
include to the cpp.

This dependency removal opened a can of worms, as few
other places were, invalidly, depending on the wallet's
header including it.

3 files changed, 10 insertions, 1 deletions

diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp
index 00b7952ca4..68f2139057 100644
--- a/src/qt/optionsmodel.cpp
+++ b/src/qt/optionsmodel.cpp
@@ -18,6 +18,7 @@
 #include <netbase.h>
 #include <txdb.h>       // for -dbcache defaults
 #include <util/string.h>
+#include <util/system.h>
 #include <validation.h> // For DEFAULT_SCRIPTCHECK_THREADS
 #include <wallet/wallet.h> // For DEFAULT_SPEND_ZEROCONF_CHANGE
 
@@ -640,6 +641,11 @@ bool OptionsModel::isRestartRequired() const
     return settings.value("fRestartRequired", false).toBool();
 }
 
+bool OptionsModel::hasSigner()
+{
+    return gArgs.GetArg("-signer", "") != "";
+}
+
 void OptionsModel::checkAndMigrate()
 {
     // Migration of default values
diff --git a/src/qt/optionsmodel.h b/src/qt/optionsmodel.h
index e36fbc5b31..ccab9c19ad 100644
--- a/src/qt/optionsmodel.h
+++ b/src/qt/optionsmodel.h
@@ -98,6 +98,9 @@ public:
     bool getEnablePSBTControls() const { return m_enable_psbt_controls; }
     const QString& getOverriddenByCommandLine() { return strOverriddenByCommandLine; }
 
+    /** Whether -signer was set or not */
+    bool hasSigner();
+
     /* Explicit setters */
     void SetPruneTargetGB(int prune_target_gb);
 
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 1604cad503..4a50416fc6 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -203,7 +203,7 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         if (model->wallet().hasExternalSigner()) {
             //: "device" usually means a hardware wallet.
             ui->sendButton->setText(tr("Sign on device"));
-            if (gArgs.GetArg("-signer", "") != "") {
+            if (model->getOptionsModel()->hasSigner()) {
                 ui->sendButton->setEnabled(true);
                 ui->sendButton->setToolTip(tr("Connect your hardware wallet first."));
             } else {