Fix: Fixing isotime_add and add zero padding for isotime [#919]

* Add nasl log domain

* Revert `ISOTIME_SIZE` from 19 to 16

Size of 19 was introduced with
f85dbd3.
PR: #252
This broke the nasl_isotime_add function.

* Add zero values at end of iso time

When time in the format like '869-10-02 12:34' or
'869-10-02 12' was given to string2isotime() the
function did not fill up the missing seconds and
minutes with zeroes.

* Fix formatting

nasl/nasl_isotime.c

@@ -63,14 +63,20 @@
 #include <time.h>
 #include <unistd.h>
 
+#undef G_LOG_DOMAIN
+/**
+ * @brief GLib logging domain.
+ */
+#define G_LOG_DOMAIN "lib  nasl"
+
 #ifndef DIM
 #define DIM(v) (sizeof (v) / sizeof ((v)[0]))
 #define DIMof(type, member) DIM (((type *) 0)->member)
 #endif
 
 /* The type used to represent the time here is a string with a fixed
    length.  */
-#define ISOTIME_SIZE 19
+#define ISOTIME_SIZE 16
 typedef char my_isotime_t[ISOTIME_SIZE];
 
 /* Correction used to map to real Julian days. */
@@ -273,11 +279,21 @@ string2isotime (my_isotime_t atime, const char *string)
   atime[9] = string[11];
   atime[10] = string[12];
   if (string[13] != ':')
-    return 13;
+    {
+      atime[11] = '0';
+      atime[12] = '0';
+      atime[13] = '0';
+      atime[14] = '0';
+      return 13;
+    }
   atime[11] = string[14];
   atime[12] = string[15];
   if (string[16] != ':')
-    return 16;
+    {
+      atime[13] = '0';
+      atime[14] = '0';
+      return 16;
+    }
   atime[13] = string[17];
   atime[14] = string[18];
   return 19;