Missing hyphen in dhcp template path. Unit tests.

This is a single character bug fix.
Broke this out into a function for testing.

internal/app/wwctl/configure/dhcp/dhcp_main_test.go

@@ -0,0 +1,25 @@
+package dhcp
+
+import (
+	"testing"
+)
+
+func TestDhcpTemplateFile(t *testing.T) {
+	tests := []struct{
+		parameter string
+		expected string
+	}{
+		{"", "/usr/local/etc/warewulf/dhcp/default-dhcpd.conf"},
+		{"default", "/usr/local/etc/warewulf/dhcp/default-dhcpd.conf"},
+		{"static", "/usr/local/etc/warewulf/dhcp/static-dhcpd.conf"},
+		{"/test/absolute/path.conf", "/test/absolute/path.conf"},
+	}
+	for _, tt := range tests {
+		actual := dhcpTemplateFile(tt.parameter)
+		if actual != tt.expected {
+			t.Errorf("dhcpTemplateFile(%v) expected: %v, actual: %v",
+				tt.parameter, tt.expected, actual)
+		}
+	}
+}
+