Improve wording of documentation of MBEDTLS_PLATFORM_GMTIME_R_ALT
* system, the implementation of mbedtls_platform_gmtime_r() will default to
* using the standard gmtime(). In this case, calls from the library to
* gmtime() will be guarded by the global mutex mbedtls_threading_gmtime_mutex
- * if MBEDTLS_THREADING_C is enabled. It is advised that calls from outside the
+ * if MBEDTLS_THREADING_C is enabled. We recommend that calls from outside the
* library are also guarded with this mutex to avoid race conditions. However,
* if the macro MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, Mbed TLS will
* unconditionally use the implementation for mbedtls_platform_gmtime_r()
