Moved begin above init, reset historic buffer sizes

src/TinyGsmClientM590.h

@@ -12,6 +12,10 @@
 
 //#define TINY_GSM_DEBUG Serial
 
+#if !defined(TINY_GSM_RX_BUFFER)
+  #define TINY_GSM_RX_BUFFER 256
+#endif
+
 #define TINY_GSM_MUX_COUNT 2
 
 #include <TinyGsmCommon.h>
@@ -117,6 +121,10 @@ public:
    * Basic functions
    */
 
+  bool begin(const char* pin = NULL) {
+    return init(pin);
+  }
+
   bool init(const char* pin = NULL) {
     DBG(GF("### TinyGSM Version:"), TINYGSM_VERSION);
     if (!testAT()) {
@@ -135,10 +143,6 @@ public:
     return true;
   }
 
-  bool begin(const char* pin = NULL) {
-    return init(pin);
-  }
-
   String getModemName() {
     return "Neoway M590";
   }
@@ -254,6 +258,7 @@ TINY_GSM_MODEM_WAIT_FOR_NETWORK()
   /*
    * GPRS functions
    */
+
   bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) {
     gprsDisconnect();