escape time variable name

Author: TomBlock

post-processing-tool/src/main/java/com/bc/fiduceo/post/plugin/era5/SatelliteFieldsConfiguration.java

@@ -208,7 +208,7 @@ String get_nwp_time_variable_name() {
     }
 
     void set_nwp_time_variable_name(String nwp_time_variable_name) {
-        this.nwp_time_variable_name = nwp_time_variable_name;
+        this.nwp_time_variable_name = NetCDFUtils.escapeVariableName(nwp_time_variable_name);
     }
 
     String get_time_variable_name() {

post-processing-tool/src/test/java/com/bc/fiduceo/post/plugin/era5/SatelliteFieldsConfigurationTest.java

@@ -289,7 +289,7 @@ public void testVerify_z_dim_name() {
     @Test
     public void testVerify_nwp_time_variable_name() {
         prepareConfig();
-        config.set_nwp_time_variable_name(null);
+        config.set_nwp_time_variable_name("");
 
         try {
             config.verify();
@@ -338,6 +338,9 @@ public void testVerify_lat_variable_name() {
     public void testSetGet_nwp_time_variable_name() {
         config.set_nwp_time_variable_name("tickTock");
         assertEquals("tickTock", config.get_nwp_time_variable_name());
+
+        config.set_nwp_time_variable_name("tick.Tock");
+        assertEquals("tick\\.Tock", config.get_nwp_time_variable_name());
     }
 
     @Test