make indentation consistent

With current Arduino, an error is triggered during use of this library:
```
TrinketReactCounter_7segment.ino adafruit:avr:gemma build output
  /home/runner/.arduino15/packages/adafruit/hardware/avr/1.4.15/libraries/Wire/USI_TWI_Master.cpp: In function 'unsigned char TinyM_USI_TWI_Master_Transfer(unsigned char)':
  /home/runner/.arduino15/packages/adafruit/hardware/avr/1.4.15/libraries/Wire/USI_TWI_Master.cpp:276:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
       while( !(PIN_USI & (1<<PIN_USI_SCL)) );// Wait for SCL to go high.
       ^~~~~
```

https://github.com/adafruit/Adafruit_Learning_System_Guides/pull/2340#issuecomment-1330719802

libraries/Wire/USI_TWI_Master.cpp

@@ -271,10 +271,10 @@ unsigned char TinyM_USI_TWI_Master_Transfer( unsigned char temp )
            (1<<USITC);                              // Toggle Clock Port.
   do
   { 
-	_delay_us(T2_TWI);
+    _delay_us(T2_TWI);
     USICR = temp;                          // Generate positve SCL edge.
     while( !(PIN_USI & (1<<PIN_USI_SCL)) );// Wait for SCL to go high.
-	_delay_us(T4_TWI);
+    _delay_us(T4_TWI);
     USICR = temp;                          // Generate negative SCL edge.
   }while( !(USISR & (1<<USIOIF)) );        // Check for transfer complete.