fix linux mix to label ellipsis

src/main/resources/com/sparrowwallet/sparrow/general.css

@@ -10,6 +10,11 @@
     -fx-pref-height: 25px;
 }
 
+.form .relaxedLabelFieldSet.fieldset:horizontal .label-container {
+    -fx-pref-width: 120px;
+    -fx-pref-height: 25px;
+}
+
 .form .fieldset:horizontal .label-container {
     -fx-pref-width: 110px;
     -fx-pref-height: 25px;

src/main/resources/com/sparrowwallet/sparrow/wallet/mixto.fxml

@@ -28,7 +28,7 @@
             </rowConstraints>
 
             <Form GridPane.columnIndex="0" GridPane.rowIndex="0">
-                <Fieldset inputGrow="SOMETIMES" text="Mix To Settings">
+                <Fieldset inputGrow="SOMETIMES" text="Mix To Settings" styleClass="relaxedLabelFieldSet">
                     <Field text="Mix to wallet:">
                         <ComboBox fx:id="mixToWallets" prefWidth="160" promptText="None available" />
                         <HelpLabel helpText="Select an open wallet to mix to."/>
@@ -41,7 +41,7 @@
             </Form>
 
             <Form GridPane.columnIndex="0" GridPane.rowIndex="1">
-                <Fieldset inputGrow="SOMETIMES" text="Postmix Wallet Settings">
+                <Fieldset inputGrow="SOMETIMES" text="Postmix Wallet Settings" styleClass="relaxedLabelFieldSet">
                     <Field text="Index range:">
                         <ComboBox fx:id="indexRange" prefWidth="160">
                             <items>